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Posted at 11:00 AM ET, 09/25/2010

Going for the gold: National hits 90+ for 67th time

By Jason Samenow

* Cool air set to arrive: Full Forecast | NatCast | UnitedCast *

Washington, D.C. has reached 90 or higher on 66 67 days in 2010, the second tied for the most on record. The previous record holder was 67 from 1980 as we've stated an untold number of times on this blog.

The forecast high today is around 89 -- oh, so close. We think there's a 40% chance Reagan National (DCA, D.C.'s "official" observing station) makes 90.

Track today's temperature each hour right here:

Evening update: Today's official high was 93 at DCA . Dulles also reached 93, breaking the previous record of 92 from 1970. It was the fourth straight day Dulles tied or broke a record high.

4:00 p.m.: As if to put an exclamation point on matching the 90+ record, it's up to 93 (the record for the date is 95 set in 1930).

2:05 p.m.: We've done it! An off-hour observation of 91 has been recorded in the last 6 hours at National according to the 2 p.m. update.

2 p.m.: 88 with an east wind still at National. Some local stations (College Park) are now touching 90. Looking good to get there?

1 p.m.: Now up to 86. This is at least going to be close.

12 p.m.: 83 again. Temp held steady probably due to influence of front. Yesterday we were at 87 at noon. We need a wind from the west to kick in to give us a bump.

11 a.m.: It's 83. Surprisingly, yesterday at this time it was just 82 on its way up to 99. But the cold front moving through the region at this very time will put the brakes on the mercury's ascent this afternoon. The question is: can sunshine and a downsloping (warming) wind from the west get us those seven degrees?

By Jason Samenow  | September 25, 2010; 11:00 AM ET
Categories:  Local Climate  
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Next: NatCast: Cloudy and cool; showers?


Minor correction for your 11 AM update: should be "brakes", not "breaks" :-)

Posted by: natsncats | September 25, 2010 12:11 PM | Report abuse

The cooler temps are slow to arrive but I think they'll keep us from getting to 90 today....the next few hours will tell..

Posted by: bodyiq | September 25, 2010 12:32 PM | Report abuse

Nooooo...I don't want to break any more records!

(unless it is regarding cold temperatures and/or snow fall.)

Posted by: dinergirl1 | September 25, 2010 12:56 PM | Report abuse

With DCA temp up to 86, NWS now calling for a high of 90.

Posted by: JerryFloyd1 | September 25, 2010 1:00 PM | Report abuse

NWS at 90, that's awesome! It does feel like it's heating up, hope we can get up there. Hope it won't be 89F just as yesterday was 99F instead of 100F.

Posted by: bastings | September 25, 2010 1:36 PM | Report abuse

Another 90deg day would TIE the record today, not break it.

Posted by: lilmacumd | September 25, 2010 1:39 PM | Report abuse

Up to 88 at DCA; my indoor/outdoor has been has high as 89.6, but it's backed off a bit.

Posted by: JerryFloyd1 | September 25, 2010 2:00 PM | Report abuse

Looks to me like the front is just now passing through D.C., a flip to west winds now should seal the deal.

Posted by: Ian-CapitalWeatherGang | September 25, 2010 2:04 PM | Report abuse

91 showing on 6 hr.. congrats us!

Posted by: Ian-CapitalWeatherGang | September 25, 2010 2:06 PM | Report abuse

Oh yay, congratulations. The 2010 summer trend of high electric bills, parched landscaping & grouchy, sticky people continues.
Send in the cooling rains ASAP.

Posted by: FIREDRAGON47 | September 25, 2010 2:14 PM | Report abuse


Now... any chance we'll eke out another 90+ when this cool weather trend ends in 10 days or so? Or is this new pattern going to establish itself?

Posted by: ennepe68 | September 25, 2010 2:32 PM | Report abuse

Since the 90-degree record has been tied, somebody please tell the stinkbugs to go elsewhere. My apt. reeks as the Glover Park StinkBug Massacre continues to play out.

(I never thought it would make it to 67 days... and if we don't see any 90 degree days 'til next July, would be fine with me.)

Posted by: JerryFloyd1 | September 25, 2010 2:42 PM | Report abuse

Sweet, I was hoping we'd tie the record!

As I posted on here yesterday, forecasters alwaaaays underestimate the highs. Alright, I know, that's not a scientific explanation. Are we experiencing warm, downsloping winds coming off the Appalachians again? That happened before the last cold front came through, when it hit a higher-than-expected 96 on September 8th.

Posted by: meteorolinguist | September 25, 2010 2:46 PM | Report abuse

Jason or others,

Is there an easy way to access a list of this year's 90 degree days, perhaps from this blog (I haven't been following the Gang religiously since the winter)?

Thanks much.

Posted by: stevie_in_gp | September 25, 2010 2:50 PM | Report abuse

if I had read the temperature tracking this morning, I could have answered my own question about downsloping winds above. Guess that's indeed what bumped up the temperature.

Posted by: meteorolinguist | September 25, 2010 2:54 PM | Report abuse

@meteorolinguist, although I'm not an expert in such matters, if you scroll the CWG map westward and soutwestward current temps seem to suggest Apps downsloping heating. A short while Front Royal was up to 95 (since dropped to 94). Charlottesville, Culpeper are also in the mid-90s and places in the eastern WV Panhandle are still in the upper 80s.

Posted by: JerryFloyd1 | September 25, 2010 2:55 PM | Report abuse

I still don't understand why National Airport is the place to record the highs and lows, esp. the highs. Seems to me with all the tarmac and reflected sunlight from the building there, the temps are artificially increased. I think somewhere in DC...maybe at the National Cathedral or at the edge of Rock Creek Park...would be a more realistic measurement of actual temperatures.

Posted by: DecafDrinker | September 25, 2010 2:55 PM | Report abuse

meteorolinguist, not sure that's really true. There may be certain patterns where highs are slightly underforecast, and actually this is probably the first time all warm season I remember seeing the models consistently forecast highs 2-5+ too low a day out. In this one CWG did pretty well.. especially in highlighting the potential to get there today early in the week when others were saying highs near 80 today. This is probably a prime day to hedge too low, even a high of 89 is 12 degrees above average and a good bit of it has to do extactly when the front comes through... west winds will only do so much, and it looks like we got 91 before even switching.

Posted by: Ian-CapitalWeatherGang | September 25, 2010 2:58 PM | Report abuse

Meteorology's an inexact science, Decaf, but not THAT inexact: there are specific ways to mitigate effects on sensing like those you describe. I'm gonna guess steps are taken . . .

(And altitude - as at the Cathedral - and vegetation/shade - as at the edge of the Park - affect "actual [local] temps" every bit as much as the man-made impediments to accuracy you mention.)

Posted by: stevie_in_gp | September 25, 2010 3:05 PM | Report abuse

Part of the issue that the models have had lately is the lack of moisture, both soil and atmosphere. This has allowed temps to be higher than first thought. IF and this is a major IF we can get these soaking rains to come north for Monday/Tuesday that should pretty much shut the door on our 90+ weather for the season. This would be due to the new pattern, available energy due to less and less solar energy available, and the increase in soil moisture that would have to be evaporated. As everyone here knows, the further we get into Autumn the harder and harder it is to get high temps above 90 for obvious reasons.

Posted by: wb1313 | September 25, 2010 3:08 PM | Report abuse

Looks as though we've tied the record...but this may be the last day, barring an October heat wave.

Rain next week may affect potential for extreme warmth later this fall since it's harder to warm the air when the soil is moist. Lots of heat goes into water's heat of vaporization, and won't warm the air or soil.

Posted by: Bombo47jea | September 25, 2010 3:10 PM | Report abuse

stevie, here's a list of 90+ days in Excel (with 1980 as well). Today is not official though..

Posted by: Ian-CapitalWeatherGang | September 25, 2010 3:14 PM | Report abuse


Best way to see all of the 90s is to go to this site:, select "Preliminary Monthly Climate Data" (under product), then select "Archived Data" (under timeframe) and then to pull up each month starting in April to see what days hit 90.

You can also see the # of instances of 90+ days by month at this link:

Posted by: Jason-CapitalWeatherGang | September 25, 2010 3:14 PM | Report abuse

The records keep coming this year. Snow,now heat. Nice reaching the 67 90-degree day maximum mark. I didn't think that record would be tied or broken in my lifetime, as it is considerably higher than second place. Then, again, I never expected that we would break the 1899 annual snowfall record.

What next? Hurricane Hazel's October 15, 1954 wind record of 78 mph sustained, 98 mph gusts at Reagan National? That seems pretty unbreakable.

Posted by: ricschwartz | September 25, 2010 3:18 PM | Report abuse

Thanks so much, Ian - it's those two days in early April that I sought to be reminded of.

(And if I remember correctly, we had some ridiculously warm days in either Jan or Feb, mixed in with the snows. Touching 80 or somesuch.)

Posted by: stevie_in_gp | September 25, 2010 3:24 PM | Report abuse

Still think 1 or 2 90 days possible. As far as rain, I'm waiting until I actually c it. Wouldn't b surpised if Sun rain is more than a few scattered showers & Mon & Tues. rains end ups being a lot less than 4cast.
Don't c any real pattern change during next 2-3 weeks. + temps & - rainfall. This will b a mild dry fall.

Posted by: VaTechBob | September 25, 2010 3:24 PM | Report abuse

And thanks, Jason.

Posted by: stevie_in_gp | September 25, 2010 3:24 PM | Report abuse

Ian, if I'm reading your table correctly, there were 21 consecutive days in 1980 (July 25 through Aug 14) when temps reached or exceeded 90 degrees. If so, this was one record we didn't exceed this year. Thanks for posting the table!

Posted by: JerryFloyd1 | September 25, 2010 3:34 PM | Report abuse

93 now with a bit more downsloping apparent.. dews dropping.

Posted by: Ian-CapitalWeatherGang | September 25, 2010 3:57 PM | Report abuse

WHY are we AGAIN in the 90s today, when 84-85 was clearly forecast for today by not only NWS but most of the local TV meterologists as well? Today was supposed to be the transition day between the heat and the cool, wet regime to follow. It appears, though, that the cold front has slowed down or stalled. Winds are currently light and variable around the area, do not show a clear or consistant W to NW direction (which rules out downsloping for the time being). So, it looks like the heat is going to be prolonged at least one more day....this tropical high appears to be just too srong to allow the cold front to make much leeway against it.

Are you guys at CWG still predicting the cool air mass to get into the region tonight? Right now, it doesn't look very likely.

Posted by: MMCarhelp | September 25, 2010 4:29 PM | Report abuse

"What next? Hurricane Hazel's October 15, 1954 wind record of 78 mph sustained, 98 mph gusts at Reagan National? That seems pretty unbreakable."

The way things have gone this year, snow, heat, super-strong thunderstorms and power outages, and the earthquake, a hurricane topping Hazel's seemingly unassailable record would not surprise me in the slightest. Though that is definitely one thing I don't want to happen!

Posted by: Murre | September 25, 2010 4:31 PM | Report abuse

Ian.....I'm not sure I agree with the current downsloping assessment (see my last post, just above). The light, variable surface winds (and 60-degree dew points) just aren't supporting that.

Posted by: MMCarhelp | September 25, 2010 4:33 PM | Report abuse

@Ian, thanks for the explanation. I forgot that the lack of soil moisture has also contributed to higher than expected temperatures, as wb1313 commented. A wet ground will use up more incoming solar energy to help evaporate the moisture...this keeps the air slightly cooler (but probably more humid), I take it?

Clarification on my previous comments: I agree that you guys do a great job updating your forecasts and you usually hit the mark pretty well. It's some other sources like TWC and Not-Always-Accuweather that have daily forecasts off by several degrees on the actual day of. But I guess that's why we've got CWG to give us more accurate, locally tailored weather info ;)

Posted by: meteorolinguist | September 25, 2010 4:36 PM | Report abuse

meteorolinguist, I agree that CWG does a good job. They weren't the ones saying that we would only hit the low-mid 80's today.......ended up being 7-8 degreees off. That was other sources.

Posted by: MMCarhelp | September 25, 2010 4:49 PM | Report abuse

MMCarhelp, downsloping is not really the driver here today I don't believe, more the remnants of the hot air mass, but post-front there was some evidence of warming. All the stations around here are west wind except DCA so I don't know why it's going between variable and south. Winds arent all that strong, usually need them to kick up more to get the most out of downsloping.

Posted by: Ian-CapitalWeatherGang | September 25, 2010 5:01 PM | Report abuse

What was the highest so far today, 93?

Posted by: JerryFloyd1 | September 25, 2010 5:20 PM | Report abuse

The high was 93 per climo report. Another stat: AVG high of 67 days 90+ 2010 v 1980... 94.2 (2010), 94.3 (1980).

Posted by: Ian-CapitalWeatherGang | September 25, 2010 5:34 PM | Report abuse

Only Mr. Q can explain this record heat, after all, we r entering the next ice age.
Can't wait 4 him 2 provide links showing all these readings r wrong.

Posted by: VaTechBob | September 25, 2010 5:36 PM | Report abuse

@decafdrinker -- the major reason to put weather stations at airports is because accurate weather observation is needed for safe aviation, albeit different information is needed. Wind speed and direction are critical because they determine which direction the planes take off and land. Ceiling (distance from clouds to ground)and visibility are important too. Temperature influences air pressure (which determines lift). Once you have an official weather station at the airport, you use it. I'm sure they control for things like blast, and reflectivity. DCA seems to be a little lower than me in Michigan Park.

Posted by: kperl | September 25, 2010 5:42 PM | Report abuse

thanks, Ian. remarkable how close so many of the 1980 and 2010 stats are. I hope I never see a summer like this one again.

But another winter like 2009-10? Bring it on!!

Posted by: JerryFloyd1 | September 25, 2010 5:49 PM | Report abuse

Ah, someone mentioned Hurricane Hazel. I am 64 and that beauty was and still is the biggest weather event of my life. Clouds so black and so close, it looked like you could touch them except that they moved by so fast it looked like you'd get carried away if you went outside. Leaves stayed "glued" to windows in some cases an inch thick. You couldn't see a thing out some windows. When the rain came it flooded streets in seconds and then it would stop for a minute or so and then repeat the process. You couldn't drive anywher and it was Friday and grocery shopping was the thing back then in 1954, so I know we didn't have dinner that night. The next morning Hazel was gone but the air was so crisp it felt wonderful unlike any other day I can remember. Men were out with axes and saws back then, trees were down everywhere. Nothing has ever equaled Hazel, so why not. When another one comes, it will be your biggest weather event as well.

Posted by: terrysb | September 25, 2010 6:11 PM | Report abuse

@kperl, true, but not universally true, for as you know NYC's official readings are taken in Central Park (although readings are certainly taken at the three major airports in the NYC area).

We had lenghty discussions about DCA's snow totals last winter, esp. after snowmageddon (was that the second one?).

But interestingly DCA's total of 17.8" was almost identical to Rosslyn's 18" for that storm. And DCA's Dec '09 total of 16.6" wasn't that much less than IAD's 18".

Still, it was the Feb 9-10 snow that really got people torqued, because IAD had 32" and most of us reported 24"-plus. Plus, if you look at historical snowfall maps, DCA usually underperforms.

I still think another poster's suggestion that the U.S. Naval Weather Observatory would be an official measuring station was the best solution.

And folks will probably zing back and forth on this topic the next time a big accumulation hits here and DCA is on the short end of the snow stick.

19 more Cooling Degree Days in DCA bringing the YTD total to 2,052. Ian or other CWGers can let us know how much average average today was.

Posted by: JerryFloyd1 | September 25, 2010 6:14 PM | Report abuse

"What next? Hurricane Hazel's October 15, 1954 wind record of 78 mph sustained, 98 mph gusts at Reagan National? That seems pretty unbreakable."

I was only 3, but I remember Hurricane Hazel because the metal chimney for our furnace system was blown off our house in Landover Hills, Md., and the fire department was summoned.

Posted by: DecafDrinker | September 25, 2010 6:37 PM | Report abuse

Somehow, like many of you, I don't feel like celebrating!

Posted by: Ann-CapitalWeatherGang | September 25, 2010 6:47 PM | Report abuse

Note: regarding today's CDDs, if the temp drops below 74 degrees before midnight, that figure could change.

Ann, when you're killing stink bugs every few minutes, it's hard to celebrate. ; ))

Posted by: JerryFloyd1 | September 25, 2010 6:58 PM | Report abuse

JerryFloyd, I think there are two main reasons why DCA underperforms on the snow totals....the adjacent river, with its relatively warm temperature, and, of course, the nearby D.C. and Crystal City heat islands. Usually, we get our major snowstorms with an E to NE wind as the low moves up the coast...and that blows first over the city and warm Potomac before it gets to the DCA weather station. The jet exhaust from so many planes, of course, also adds to the local heat around the airport itelf. The same factors also help to keep the temperature up at night.

Posted by: MMCarhelp | September 25, 2010 7:14 PM | Report abuse

Every location has its quirks that are local micro-climate deals. As far as temps, I think DCA is pretty representative.. perhaps moreso than putting a sensor in the middle of Rock Creek Park. Being right next to the river certainly plays some role, you see it with heat days and a switch in winds from/off the river and it probably plays a part in the lower snow totals in winter. On a hot day though most of the city temps are pretty similar or even hotter (probabably somewhat influenced by pavement etc). Jet exhaust is a non factor IMO.

Posted by: Ian-CapitalWeatherGang | September 25, 2010 7:24 PM | Report abuse

Ok, so when is our next chance to actually break the record? Gotta go for it now. After that, let it snow!

Posted by: bodyiq | September 25, 2010 7:27 PM | Report abuse

This has been the most miserable summer I can remember and I did not appreciate the heat at the book fest. However, go big or home home. What are the chances of breaking the record?

Posted by: SPS1 | September 25, 2010 7:28 PM | Report abuse

This must be punishment for hoping we beat the snowfall totals last winter. Ugh...

Posted by: B-Kraemer | September 25, 2010 7:39 PM | Report abuse

The way the upcoming patterns are looking to me I don't think we will hit 90 again this season. With next week's significant rain coming, soil moisture will be up and that will help keep the temperatures lower. Personally I sure hope so - bring on the snow! Kevin Gaithersburg Maryland

Posted by: walrusman444 | September 25, 2010 8:20 PM | Report abuse

Really liking the 100% chance of rain I see here on the site for Monday and Tuesday. I can't wait!

Posted by: natsncats | September 25, 2010 9:27 PM | Report abuse

Seems like the front which was supposed to pass this morning, has only just cleared DC!

Posted by: HenryFPotter | September 25, 2010 10:16 PM | Report abuse

Remember last winter when we had all of the snow and COLD! weather? And we said we'd never complain about warm weather again? HA! Good-bye, good riddance to this stinking, hot, humid summer.

I, also, remember Hurricane Hazel. We lived in an apt. on University Blvd. close to Riggs Rd. I remember my mother promised to fix BLTs for lunch, but the electric went out and that was the end of that!

Isn't life strange... My mother died when I was seven, and that's one of the few memories I have of her. Thank you, Hurricane Hazel.

Posted by: waterfrontproperty | September 25, 2010 10:36 PM | Report abuse

"I, also, remember Hurricane Hazel. We lived in an apt. on University Blvd. close to Riggs Rd. I remember my mother promised to fix BLTs for lunch, but the electric went out and that was the end of that!

Isn't life strange... My mother died when I was seven, and that's one of the few memories I have of her. Thank you, Hurricane Hazel." ---What a memory to have, waterfrontproperty. Thanks for sharing it!

Posted by: DecafDrinker | September 25, 2010 10:56 PM | Report abuse

The latest 90 degree high temperature day on record at DCA (Reagan) is Oct. 11th (1919) only a few weeks away. The current change in pattern does not indicate any above normal temperatures for awhile. It will be difficult to have one more 90 degree high temperature day this year.

Posted by: WayneP1369 | September 27, 2010 1:12 PM | Report abuse

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