If you watch KPRC 2, then you may have noticed lately that sometimes the high temperature for the day doesn’t actually occur until after 5 p.m. and, often, closer to 6 p.m. Despite the sun being highest in the sky around noon, the heat builds all day to its crescendo in the later afternoon. In turn, the earth cools all night so that our coolest temperatures are usually right at dawn (ask walkers and joggers). This daily lagging effect applies to our seasons, also. It’s called the seasonal lag effect.
You know of the summer solstice around June 20, being the longest day of the year, but yet those days of the most sunlight aren’t usually our hottest. The Earth continues to build up its heat and then that heat begins to release in August, and that is why August is usually our hottest month of the year. In fact, Houston’s average high temperature for June is 92.3° while July is 94.5° and August marks in at 94.9° -- just slightly above.
All this brings us to the hottest summers we’ve seen in recent history: 1980, 1998, 2011 and right now. I made a chart of 100+ degree days, and you can see below the results:
You can see that July in two of our years accounted for more 100°+ days than August, while 2011 had an August to be respected.
Again, July for 1980 and 1998 had a warmer average high temperature than August. Yet 2011 was ferocious.
So what to make of this? While seasonal lag certainly occurs and August is usually our hottest month, it’s only by a little bit. July is one month that we deal with Saharan dust which doesn’t help in getting rain in here. Hopefully we’ll see a better rain chance tomorrow.
For now, we’re looking a lot like 1980 and 1998, which had very hot June and July months, but did not build up to an extremely hot August like 2011. I think the reason that 2011 was so tough is that we’d basically been in a drought since 2008 after Hurricane Ike brought on a dry pattern. We haven’t had that kind of multi-year drought, even though it’s certainly very dry right now.
I’ll keep watching the numbers, but if you’re wondering if August will be worse than July, I think the answer is no. I can’t promise it will be a lot better, but with any luck, we’ll avoid 30 days of 100° temperatures!