With higher humidity & decent to high soil moisture overall through the area, notice the lows in the 60s & highs in the 80s. This is a night to day turn of roughly 20 degrees.
However, when you have a major drought going on, there are often WIDE temperature swings...........
First, here are the ecorded lows & highs for Thursday:
Recorded lows & highs today:
When soils are very dry & vegetation withering, there is a lack of moisture evaporating or transpiring. This only makes the air drier, which dries soils further & enhances the drought. This drought enhancement continues to raise temperatures as less moisture in the air makes it easier to heat up. So, drought feeds on itself & is self-perpetuating. This often continues unless you have a long-term change in the pattern.
Lack of moisture makes the temperature tank at night, however. Moisture stores heat energy & lack of it makes it hard to store any heat. Clear skies often accompany dry, droughty weather, only allowing the temperature to drop further. This same situation is prevalent in deserts where highs in the 100s will drop to the 40s & 50s at night, especially in high elevation where the air this "thinner".
The worst droughts have shown impressive desert-like temperature changes between night & day in our area.
There were also a lot of fires in the area with lots of smoke reported in many 19th century weather records for our area.
Check out these two examples from early August 1887 & 1894.
August 9, 1887
Extremely dry soils from the Extreme to Exceptional Drought across the area caused the largest temperature increase from the morning low to the afternoon high (without any front) at West Lafayette.
At the Purdue University station, after a morning low of 54, the temperature reached 101 during the afternoon, a rise of 47 degrees.
Such dryness often produces large temperature differences with stagnant surface high pressure, similar to deserts.
August 9, 1894
Drought across the region (long drought 1894-96) caused wide swings between morning lows & afternoon highs. With hazy sun, after a morning low of 53 at West Lafayette, the afternoon high reached 93.
On the 8 & 9th, highs of 99 & 100 occurred with lows of 60 & 66 as smokey, hazy, sunny conditions hovered over the dry, droughty soils.
From late June to early August, smoke was reported on 13 days at Purdue University as forests burned in the Ozarks, Great Lakes & marshes & prairies in Newton & Jasper County burned.