BDL June Recap

Happy Independence Day to all! I hope you have a safe and happy day. The region will see warm but clear weather, with some potential isolated storms in mountain areas.

As promised, this post will be my recap of June 2020 weather at Bradley International Airport (BDL) in Windsor Locks, CT. (See this link to read my June recap for Burlington, VT). Here is a look at the temperature graph for the month.

BDL June 2020 temperature graph (xmACIS)

You can see that temperatures at the beginning of the month were impressively cold (at record levels), while they gradually increased to above normal by the end of the monty. In fact, the low temperature on June 1 was 37 °F, which set a record for that date, and tied the all-time record low temperature for the month of June at BDL. Speaking of record lows, on June 2, we tied the record low temperature for that date at BDL, at 42 °F. 

To flip the switch, the heat didn't really come until mid-month, but when it did, it came with a vengeance. With temperatures above 90 °F each day from June 20 to June 24, we had one 5-day heat wave, which included one day (the 22nd) where the temperature reached 94 °F. As a whole, the mean temperature for BDL for June 2020 was 70.7 °F, when normal for June is 68.5 °F, giving us a departure from normal of 2.2 °F. Temperatures really trended upwards as the month progressed (which is to be expected for June), but I think this trend was amplified during 2020. I decided to do some further analysis on this to see just how much this trend was amplified this year.

Linear model for historical average June temps (Blue) and linear model for June 2020 temps (Red)

In the above graph, the blue line shows the historical trend of average temperatures throughout the month of June. Its slope is 0.283471, meaning that with each new day in June, we'd expect the temperature to increase by 0.283471 °F. This month, however, the linear model shows that the temperature increased by 0.399333 °F each day, as evidenced by the slope of the red line in the above graph. This isn't too telling about the nature of the weather at BDL this June, but I find it interesting that temperatures throughout the month warmed at a much rate faster than what is expected.

As for precipitation, June 2020 was a very dry month in CT. We only saw 1.24 inches of rain during June 2020, when normal is 4.34 in.

BDL June 2020 precipitation chart (xmACIS)

In the above graph, the brown line is normal accumulated precipitation for the month, and the green line shows the June 2020 accumulated precipitation. Clearly we were well below normal for the entire month. Similar to what we saw in Burlington, VT, there was a prolonged dry spell from June 12 to June 26. There were only 5 days during the month when we saw measurable precipitation, with the greatest rainfall being 0.42 inches on the last day of the month. This paucity of rain caused much of the state to enter a drought. I do believe that this shortage of rainfall that we saw at BDL was more extreme than the rest of the state, as evidenced by this map.

June 2020 observed total precipitation map (NWS)

The area of green that you see near the Mass. border is where BDL is, and it appears to have seen the least amount of rain in the state during the month. Isolated areas in the state (the the red on the map) saw much more rainfall during June 2020, particularly due to intense, localized storms at the very end of the month.

Overall, I'd characterize June 2020 at BDL as being warm and dry, with the usual summertime convective storms. We saw a 5-day heat wave, along with record cold temperatures at the beginning of the month. It'll be interesting and exciting to see what July has in store!