Climate change in Minnesota is clearly seen at night

As we method the top of the rising season for a lot of come Tuesday evening, it’s value taking a step again and all of the methods to measure simply how lengthy the nice and cozy season was this 12 months and the warming pattern we’re witnessing. 

We all know temperatures are rising. The extremes and common temperature rankings get numerous consideration, and may, however simply as necessary is the period of heat.

Twenty-twenty-two went down as a 12 months with a scorching summer season within the Twin Cities, although statewide it was a combined map. Northeast Minnesota noticed kind of a close to regular – that’s the trendy 30-year common – common summer season temperature whereas southwest Minnesota up by way of the Twin Cities had a effectively above regular averaged summer season temperature.

It was not our hottest summer season on file like final 12 months. That was final 12 months. The Summer season of 2022 was concerning the seventeenth warmest for the Twin Cities, which is within the prime 11% within the record-keeping period. You might, nevertheless, make a very good argument for it being the longest summer season on file.

Whereas there’s not an official definition for size of summer season, and it might differ by the place on the planet you might be, let’s say we measure it by the variety of consecutive days at 70°+ excessive temperatures. 

This 12 months the Twin Cities had 119 consecutive days of excessive temperatures at 70°+, from Might 26 to Sept. 22, probably the most ever on file. 

The typical variety of consecutive 70s within the Twin Cities since 2000 is about 64 days, up from the historic common of simply 48. So this 12 months noticed nearly DOUBLE than even the extra trendy averages. Even the decrease trendy common of 64 days is up 31% from the historic common. That’s an additional 2+ weeks of heat climate.

The humorous factor is, nearly it doesn’t matter what determine we take a look at you give you an identical variety of about two additional weeks. Even when we simply take a look at the overall variety of 70-degree days in a mean 12 months, that quantity too has elevated by about two weeks value.

In fact, the newest variety of relevance this week, and within the coming weeks is the rising season, i.e. consecutive days above freezing. No shock, the rising season is getting longer – and by fairly a bit. We’ve added as much as a number of weeks to the rising season within the final 50 years.

The opposite stat that caught my eye not too long ago was the unusually lengthy stretch and not using a chilly evening, what I deem to be within the 40s or colder. We had 118 consecutive nights the place the in a single day low stayed at 50 or hotter within the Twin Cities. The one summers on file with extra are 2016, 2018 and 1881. 

Contemplating the impacts of human-caused local weather change in 1881 was minimal or non-existent, that was fairly the season. Eight of the highest 10 are simply since 2000, so earlier than somebody tries to yell that it occurred as soon as earlier than, way back, it merely doesn’t match the traits and full context of knowledge.

Once we look outdoors the Twin Cities, the place the city warmth island (UHI) doesn’t have any impression, we see comparable traits however clearly shorter seasons. Saint Cloud for instance will get cooler than the Twin Cities most nights as a result of it being a bit farther north and outdoors of the massive sprawl of the city Twin Cities metro. There you see an enormous enhance within the size of the nice and cozy evening season. In reality, it’s a staggering triple the worth of fifty years in the past.

In different phrases, 50 years in the past you would mainly depend on simply the warmest few weeks of summer season staying above 50 at evening. However now? That season has expanded to incorporate all of July and into mid-August on common.

Going again to the rising season knowledge, we will see the same sample in St. Cloud. Whereas the rising season of central Minnesota is shorter than the Twin Cities space, it’s nonetheless elevated by almost three weeks since 1970. 

Add to all of this one other heat month this September, together with that file excessive of 92 final week, and also you begin to see the massive, difficult image of local weather change in Minnesota.