Putting the heat into perspective

100 degrees is not a common occurrence in the Twin Cities, even less so in June. We broke other records that may have gone otherwise unnoticed.

Putting Monday’s 101 degree high into perspective

The recent heat broke not one but two records Monday. We broke the record high, which had been 98 in 1933 and the record warm low at 79, which was 75 set in 1943. Saint Cloud also hit 101 degrees and broke their record for the date.

100 degrees is pretty rare in the Twin Cities. In our modern averages (1991-2020) it happens about once every five years. The 1930s of course were notorious for hitting the 100s many times. The 1980s also, had a fair amount. Hitting 100 in June is even less common. On that rare occasion we hit 100 degrees, 71 percent of the time it’s in July.

Considering June is our fastest warming summer month (from a climate change perspective), this may be at least part of the explanation for the extreme heat this year and the second hottest June on record we had last year in 2021.

Fingerprints of climate change?

When it comes to attributing the triple digits to climate change, things can get a little bit more murky. We know in the 1930s there were lots of days of extreme heat and continue to hold many of our hottest records. There have also been studies done now that attribute at least some of the warming of the 1930s to human causes; both in terms of burning fossil fuels and land use.

A new measure of climate change attribution from Climate Central uses lots of data to come up with a ‘Climate Shift Index.’ The climate signal is there for Monday’s high temperature at a one or two (a higher number indicates the strongest attribution).

The real eye-popping figure comes when we look at the record warm overnight low Sunday night/early Monday.

For the sake of comparison, here’s the attribution of mid December (2021) high temperatures. That was when we had Minnesota’s first-ever recorded December tornadoes.

We know Minnesota is warming, especially in winter, but also in summer. Day to day natural weather swings still occur, but it’s undeniable that a warming climate is making heat waves longer and more severe in many parts of the world and that will also impact Minnesota.