Summer is over, or is it? From a climatological perspective, summer is considered to be the calendar months of Jun, Jul, Aug; but, of course, the calendar says something different, with the equinox this year on Sep 23. For our purposes, we will go with the climatological definition as temperatures typically start dropping off rather quickly during September. For example, the normal daytime high to start the month is 90, but by the time the equinox arrives it has dropped to 81.
So, will start off with a look back at August which turned in an average temperature about 3 degrees below normal and a total precipitation that was more than 2” above normal; in other words, a relatively cool, wet month. Of course, the rainfall was widely varied with some winners and losers in that regard, as you can see by the 30-day rainfall map courtesy of the OK Mesonet. Of particular note are the very dry conditions over the SC and SE sections of the state in contrast to the much wetter conditions elsewhere.
August also posted 21 days with below normal temperatures and one record morning low was set. Interestingly, 18 of the last 21 days of the month were cooler than normal and we had a streak going for more than a week in which the temperature was running second coolest ever for that time of year.
As for triple digit days during the warm season, that is shown on the next map. As might be expected, the drier locations had more triple digit days, and for NE OK, many locations had none at all. The 3 in the immediate Tulsa area occurred on 3 consecutive days in early August and can, to a certain extent, be attributed to the urban heat island as none of the rural locations surrounding Tulsa had any triple digits at all.
The 3 triple digit days are the fewest since the summer of 2004 when Tulsa posted a goose egg in that category. Although the triple digit days were low and not extreme - with the highest at 102 - the heat index on one of those days more than made up for it as heat index values exceeded 115, which is very unusual for this area.
Also, triple digits are still possible as 100-degree temperatures have occurred as late as Sep 28. However, although the current weather pattern will support above normal temperatures for the next two weeks, triple digits do not appear likely - and I would be surprised if we have any more this year.
As for the summer as a whole, it will go down in the record books as slightly warmer than normal as the very cool August was offset by an equally warm June, and July was also warmer than normal. The total precipitation as recorded at the airport was 16.65” making this the 13th wettest summer, but again, there is considerable variation in those precipitation totals around the state. Notice the 90-day precipitation map for example where considerable variation in nearby locations is apparent.
As mentioned above, temperatures look to be running above normal all this week and possibly into the following week as well. The warmer than normal temperatures this week will also be accompanied by southerly breezes keeping our dew point temperature in the 60s to near 70. That means the heat index will be a factor each day with values reaching the upper 90s to near 100 at times, so take it easy with the outdoor activities.
As for our chances of rain, the current pattern does not support anything more than an isolated shower or storm at best and mainly over the far eastern counties on any given day. As you can see, the 7-day QPF map has us pretty much high and dry.
So, stay tuned and check back for updates.