December Discobs 2025

[North Balti Zen]

Was 12 when I left the house in Fallston at 8 am.

[wxdude64]

Just broke over 32 degrees at 10:30 am. That is a bit over 56 hours below freezing, 42 hours under 20 and 11 hours below 10 degrees. Not a bad run before hitting the winter solstice. 

[Cobalt]

BWI has just recorded its 10th coldest 1st half of December, with an average temperature of 31.4F. DCA comes in at 19th coldest (34.4F)

 

Just as compelling are the stats for max daytime temperatures so far this month. BWI's mark of 45F ties with 1904 for the lowest high temperature seen in the first half of December. DCA 2nd lowest (46F). 

As for the upcoming warmup.. DCA's 30 year average max temperature for the 2nd half of December is 64F, so what might feel like a Holidays "torch" is actually not too uncommon. 

 

[Eskimo Joe]

Looks like we may get some low topped convection early Friday AM with the frontal passage?

[WEATHER53]

3 hours ago, Cobalt said:

BWI has just recorded its 10th coldest 1st half of December, with an average temperature of 31.4F. DCA comes in at 19th coldest (34.4F)

 

Just as compelling are the stats for max daytime temperatures so far this month. BWI's mark of 45F ties with 1904 for the lowest high temperature seen in the first half of December. DCA 2nd lowest (46F). 

As for the upcoming warmup.. DCA's 30 year average max temperature for the 2nd half of December is 64F, so what might feel like a Holidays "torch" is actually not too uncommon. 

 

That’s incorrect

DCA normal high temp for 2nd half of December is no where near 64 , more like 49 

[CAPE]

34 is the high for the day.

Enjoying the last day of full snow cover. Some bare spots here and there, but pretty impressive how long 2" or less can hang on this time of year with the cold and low sun. Pretty rare to see lately before Xmas.

[pazzo83]

17 minutes ago, WEATHER53 said:

That’s incorrect

DCA normal high temp for 2nd half of December is no where near 64 , more like 49 

he means the average maximum temperature over the entire half month period - meaning, what's the warmest it will get, on average, for the last half of December.  Mid 60s seems right - meaning, on average, DC should see one day where it hits 64F during this period.

[pazzo83]

DCA's mean maximum for the entire month of December is 67F.

[Terpeast]

After a low of 13.5, temp is 41 which feels very comfortable compared to yesterday. 

[pazzo83]

5 minutes ago, Terpeast said:

After a low of 13.5, temp is 41 which feels very comfortable compared to yesterday. 

the human body acclimates remarkably quickly.

[Weather Will]

Wet Thursday evening and Friday am on tap....wash the salt away. WB 18Z 12K NAM

[CAPE]

31 at 4pm. This view will be gone in the next 24 hours, but nice while it lasted. 

[dailylurker]

I drove out to Cunningham Falls this morning for a day of hiking at higher elevation. It wanted to extend the deep winter period one more day by headed out there. It was an interesting drive out there. The snow distribution from here to there was super spotty. As soon as I got on 97 north from Crofton the snow really thinned out. It didn't increase again until I got up on 70 and got into higher elevation. Once I got into the Frederick valley it got super thin and spotty again. As soon as I gained elevation going up into the mountains it increased again. Their was about 4" of powdery snow up at the fall. The falls are at like 1200'. It was 27 at that elevation. I hiked up to 1500' and suddenly it was above freezing up there. It was colder in the low spots between ridges. The falls were completely frozen. 

[dailylurker]

[WEATHER53]

2 hours ago, pazzo83 said:

he means the average maximum temperature over the entire half month period - meaning, what's the warmest it will get, on average, for the last half of December.  Mid 60s seems right - meaning, on average, DC should see one day where it hits 64F during this period.

Thats not what he said and I don’t think and have never seen any calculation of what is the average of the highest temps for the second half of the month 

[WEATHER53]

2 hours ago, pazzo83 said:

DCA's mean maximum for the entire month of December is 67F.

If you are stating that is the  average of any record setting daily highs then that is probably correct.  However the mean or average max daily high is no where near that

[pazzo83]

2 hours ago, WEATHER53 said:

If you are stating that is the  average of any record setting daily highs then that is probably correct.  However the mean or average max daily high is no where near that

no - it's the mean maximum temperature for the entire month.  Which means - in the last 30 years, on average, the maximum temperature observed at DCA was 67F.  In July, DCA's mean maximum monthly temperature is 98F - which means that's on average as hot as it gets here in July.  You can see here: https://en.wikipedia.org/wiki/Washington,_D.C.#Climate

The row in question in the climate table is "Mean maximum"

[pazzo83]

2 hours ago, WEATHER53 said:

Thats not what he said and I don’t think and have never seen any calculation of what is the average of the highest temps for the second half of the month 

you would take the maximum temperature observed from Dec 15-31 in each year from 1991 to 2020 and calculate the average.

[wxdude64]

Went from 38 at 4 pm to 28 at 5:15 as the sun slipped behind the mountain this afternoon. Currently 26.4/12.0 at 8 pm. 

[Kay]

Another ice pic, from yesterday. Sun breaking through abundant clouds/virga made for an eerie light. 

[wxdude64]

56 minutes ago, wxdude64 said:

Went from 38 at 4 pm to 28 at 5:15 as the sun slipped behind the mountain this afternoon. Currently 26.4/12.0 at 8 pm. 

Clouded over and temp and DP immediately went up, now 29.0/16.7 at 9 pm. 

[Jrlg1181]

Just drove home from work crossing Afton Mt... Temp went from mid / upper 20s in Charlottesville to 39 on the mountain back down to 25 in Waynesboro ( according to the car temp gauge ) ... Definitely warmer air is moving in aloft..

[wxdude64]

7 hours ago, Jrlg1181 said:

Just drove home from work crossing Afton Mt... Temp went from mid / upper 20s in Charlottesville to 39 on the mountain back down to 25 in Waynesboro ( according to the car temp gauge ) ... Definitely warmer air is moving in aloft..

After dropping back into the mid 20's early last evening I played a yo-yo game on temps with a small steady climb. It seemed quite dependent on the cloud cover overhead too. 33.5 at 7 am here with mostly cloudy skies and an absolutely stunning red/pink sky to the east as dawn broke. 

[GramaxRefugee]

My crusty snow pack refuses to budge from 2"; (past 2 days).  Probably lose some today.

[kgottwald]

Thought we'd get more sun today. Nothing but gloom after 9:30 this morning.

[bncho]

WxBELL has GFS AI and its ensemble!

[wxdude64]

Hit 50.6 degrees briefly about noon here, first time above 50 since 11/27. Was a high haze/cloud cover, now lowered clouds, looks like rain soon? although with an 21 degree DP it'll be virga. Temp down to 47.8 degrees at 1:30 pm.

[WEATHER53]

Cold down here in the holler at head of the crick with high of 49 and low of 21. Not a big departure but another consecutive negative 

2” remaining snow over at Frederuck house doing its job, 42 max so far there

[Terpeast]

Fell short of the forecasted high of 51, only made it to 48. 

[T. August]

High of 43.2°, currently 40.4°.