The onset of fall weather came abruptly last night. After more than 90 days when low temperatures failed to even reach the 50s in D.C., we dipped all the way into the 40s. And this afternoon’s temperatures are stuggling to reach the mid-60s, the coolest since early May.

Capital Weather Gang reader, one Melissa Weitz, is none too happy about fall’s arrival. She posted this to Facebook exactly ten days ago, when the high only managed 67 degrees and we picked up nearly an inch of rain:

Fall weather conditions appear to be forming in DC. Models are showing that fall is on a trajectory to directly hit the east coast within the next few weeks! Residents are advised to discard any flip flops, iced coffee beverages, and rooftop party plans, and to be ready with sweaters to put on and take off and on and off, and umbrellas to put up then down then up then down, as each minute decides if it is going to be hot or cold and rainy or dry. More complaining to follow.

Do you share Melissa’s angst about fall? Vote in our poll.

So what are the odds of more hot, summery days?

The likelihood of seeing more 90 degree days is not great. CWG’s Ian Livingston addressed this matter in a blog post yesterday. Here’s the relevant excerpt:

For those who dislike summer heat, perhaps the best news is that 90-degree days are almost out the door in September, if not already done entirely. Averaging three such days a year, it is the last month we would typically expect to see these temperatures. While 90 degree or higher days can happen into October, it is so infrequent as to barely register an average of just above zero.

Ian tells me after September 15, we average less than one day above 90 degrees and after September 20, just about one every other year.

But those of you who like warmth should not completely despair: we’re very likely to have at least 4-8 more 80 degree days. CWG’s Matt Ross posted the following to Facebook yesterday:

Average number of 80 degree days from September 20th forward: 7.2
Median: 6
Chance of at least 1: ~100%
Chance of at least 4: 80%
Chance of at least 8: 40%

In fact, next week, the prospects for more 80-degree weather look pretty good as the jet stream jogs to the north and southerly flow returns.

And let’s not forget last year, when we had five 90+ days after September 15 (the record is 8 in 1941).