After two days of sweltering heat and humidity, what's next in the forecast?
Heat index values Wednesday afternoon.
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A late summer scorcher is bringing relentless heat to the state. Tuesday broke records for many towns in Minnesota and the heat and humidity is sticking around.
One of the most oppressively hot and humid places Wednesday afternoon was the city of Preston in the southeast corner of Minnesota. The temperature was 90 with a 79-degree dewpoint and a heat index of 105.
Excessive heat warnings and heat advisories were posted not only for southern and central Minnesota but for other parts of the nation. So when will we get some relief?
MPR Chief Meteorologist Paul Huttner joined MPR News Host Cathy Wurzer with answers.
Use the audio player above to listen to the full conversation.
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Audio transcript
[MUSIC PLAYING] CATHY WURZER: All right. Let's dive into the weather. Although, a cool pool might be nice about now. Yesterday, ended up being a record-breaking day for many towns in Minnesota. And the heat and humidity is sticking around.
One of the most oppressively hot and humid places right now is Preston, Minnesota in the southeast corner. It's 90 with a 79-degree dew point. That's tropical. The heat index, what it feels like in Preston-- 105 degrees. Excessive heat warnings and heat advisories are posed to not only for our region but other parts of the nation.
So when will we finally get some relief? MPR chief meteorologist, Paul Huttner, joins us with some answers. Is it hot enough for you?
PAUL HUTTNER: Oh, way hot enough for me. But I know for you, you love this. We call this Wurzer weather when it gets this hot?
CATHY WURZER: I have to say. Even yesterday was maybe a tad hot for me.
PAUL HUTTNER: [LAUGHS]
CATHY WURZER: [CHUCKLES]
PAUL HUTTNER: Yeah. You and everybody else, I think, Cathy. I mean, this is peak summer in Minnesota when it comes to heat. I mean, call it a record-heat dome, a heat-pump high, whatever you want. This thing has just been sitting over the central US, and it finally edged north into Minnesota this week.
You mentioned the 98, that was a record yesterday at Twin Cities airport, hottest day of 2023 so far, and probably the hottest of the year, I think. It was also the warmest August day in 35 years. The last time we were that hot in August was August 7 of 1988. That was, of course, the hottest summer on record. We had 44 days of 90 degrees plus that summer.
We've had 26 days. So we've already hit 90 today. So today is day 26 of 90-degree or hotter in the Twin Cities. And by the way, Cathy, 30 days would put us in the top 10 for 90-degree days in the summer.
But wow, those heat index values yesterday, 120 at Mankato. Hennepin Mesonet has weather stations around Hennepin County. Heat index values yesterday, 114 to 119, right in the Twin Cities. And we're sitting here now at 93 at last hour, 73 dew point, 101 heat index. But hey, if you're north of the Twin Cities, you're wondering what all the fuss is about right there in the 60s North, even 70s and 80s Northern Metro. There's clouds and fog just north of the Twin Cities today.
CATHY WURZER: OK. I thought that the dew points, especially the early, early this morning when we were up doing Morning Edition, were just oppressive.
PAUL HUTTNER: Yeah. And we did hit 80 for dew points in the Twin Cities yesterday, parts of the Twin Cities, and also Mankato. And you know what? It was interesting because a lot of meteorologists kind of backchannel talking. The dew point sensors hit 92 to 93 degrees in Western and Northwest Iowa yesterday at multiple sites, different times.
And there might be a couple of reasons for that. One could be sensor issues. The calibration could be a little bit off. They'll probably send field techs out to check those.
But corn sweat is definitely a factor juicing this air mass. An acre of corn can put out 3,000 to 4,000 gallons of water during a day. It's a real efficient evapotranspirator. So it pulls moisture from the soil, sweats it out through the plant, and that goes into the lower atmosphere. And there's a sea of corn, like 92 million acres of corn in the upper Midwest.
Pete Boulay at the Minnesota State Climate office did an experiment several years ago. He went out over the cornfield. He swung what's called a sling psychrometer and measured the dew points right over the cornfield on a pretty calm day. He found dew point readings 1 to 5 degrees higher right over the cornfield than in the air mass away from the cornfield. So it's a real thing with corn sweat.
And finally, Cathy, the Gulf of Mexico water temperatures are around 90 degrees. They're at record levels. That's superheated Gulf of Mexico has been pumping moisture advection, moisture into the central plains and right through into the upper Midwest. So there are a couple of factors at work here that we're seeing these potentially near record dew points down in Iowa. I don't think it's all sensor issues, but it might be some.
CATHY WURZER: Wow. So when might we get some relief?
PAUL HUTTNER: Yeah, it's coming. It's going to be slow, though. So I think we're 97, 98 today in the Twin Cities. As I said, much cooler just north of the Twin Cities and through most of Central and Northern Minnesota.
Tomorrow, sunny, not quite as hot. Around 90. And then Friday, when I think you and I will be chatting out at the State Fair, which will be fun, 88 for the high. Should be in the 80s about the time we're on the air around 11:00 AM. And then the weekend looks great, Cathy. Cooler. Pleasantly cooler. 70s to around 80 this weekend.
CATHY WURZER: Does it usually get-- if my memory serves me, it usually gets pretty hot those first few days of the fair,
PAUL HUTTNER: Yeah, it certainly can, and it has in the past. By the way, I think Saturday through Tuesday will be the most comfortable days this year. So it looks great. I think we're going to see some big attendance numbers this weekend, Saturday and Sunday, highs in the 70s to low 80s.
But Minnesota DNR Climate Group has put out some pretty cool stats on the State Fair. The hottest ever was 104 back on September 10, 1931, and that year was the hottest year. The average high that year was 92.6 degrees.
But recently, in 2013, we had the most 90-degree days, six of them during the run of the fair. That was the third warmest State Fair. And just for the flip side of the coin, Cathy, the coldest day ever, can you imagine 52 degrees for a high at the fair, September 7 of 1911?
CATHY WURZER: That's not fun. It's the fair. You want to be that cold. All right. But before you go, what's on Climate Cast?
PAUL HUTTNER: Yeah. There's a backlog of renewable energy projects around the country. Wind and solar are trying to get on the grid. The process has been slow. The Federal Energy Regulatory Commission is coming up with some new regulations, try to speed that up. So we'll talk about that tomorrow on Climate Cast during All Things Considered.
CATHY WURZER: All right, Paul Huttner. And again, I'll see you Friday at 11:00 AM at the MPR booth.
PAUL HUTTNER: Looking forward to it. Thanks C.
CATHY WURZER: All right. That's our chief meteorologist, Paul Huttner.
One of the most oppressively hot and humid places right now is Preston, Minnesota in the southeast corner. It's 90 with a 79-degree dew point. That's tropical. The heat index, what it feels like in Preston-- 105 degrees. Excessive heat warnings and heat advisories are posed to not only for our region but other parts of the nation.
So when will we finally get some relief? MPR chief meteorologist, Paul Huttner, joins us with some answers. Is it hot enough for you?
PAUL HUTTNER: Oh, way hot enough for me. But I know for you, you love this. We call this Wurzer weather when it gets this hot?
CATHY WURZER: I have to say. Even yesterday was maybe a tad hot for me.
PAUL HUTTNER: [LAUGHS]
CATHY WURZER: [CHUCKLES]
PAUL HUTTNER: Yeah. You and everybody else, I think, Cathy. I mean, this is peak summer in Minnesota when it comes to heat. I mean, call it a record-heat dome, a heat-pump high, whatever you want. This thing has just been sitting over the central US, and it finally edged north into Minnesota this week.
You mentioned the 98, that was a record yesterday at Twin Cities airport, hottest day of 2023 so far, and probably the hottest of the year, I think. It was also the warmest August day in 35 years. The last time we were that hot in August was August 7 of 1988. That was, of course, the hottest summer on record. We had 44 days of 90 degrees plus that summer.
We've had 26 days. So we've already hit 90 today. So today is day 26 of 90-degree or hotter in the Twin Cities. And by the way, Cathy, 30 days would put us in the top 10 for 90-degree days in the summer.
But wow, those heat index values yesterday, 120 at Mankato. Hennepin Mesonet has weather stations around Hennepin County. Heat index values yesterday, 114 to 119, right in the Twin Cities. And we're sitting here now at 93 at last hour, 73 dew point, 101 heat index. But hey, if you're north of the Twin Cities, you're wondering what all the fuss is about right there in the 60s North, even 70s and 80s Northern Metro. There's clouds and fog just north of the Twin Cities today.
CATHY WURZER: OK. I thought that the dew points, especially the early, early this morning when we were up doing Morning Edition, were just oppressive.
PAUL HUTTNER: Yeah. And we did hit 80 for dew points in the Twin Cities yesterday, parts of the Twin Cities, and also Mankato. And you know what? It was interesting because a lot of meteorologists kind of backchannel talking. The dew point sensors hit 92 to 93 degrees in Western and Northwest Iowa yesterday at multiple sites, different times.
And there might be a couple of reasons for that. One could be sensor issues. The calibration could be a little bit off. They'll probably send field techs out to check those.
But corn sweat is definitely a factor juicing this air mass. An acre of corn can put out 3,000 to 4,000 gallons of water during a day. It's a real efficient evapotranspirator. So it pulls moisture from the soil, sweats it out through the plant, and that goes into the lower atmosphere. And there's a sea of corn, like 92 million acres of corn in the upper Midwest.
Pete Boulay at the Minnesota State Climate office did an experiment several years ago. He went out over the cornfield. He swung what's called a sling psychrometer and measured the dew points right over the cornfield on a pretty calm day. He found dew point readings 1 to 5 degrees higher right over the cornfield than in the air mass away from the cornfield. So it's a real thing with corn sweat.
And finally, Cathy, the Gulf of Mexico water temperatures are around 90 degrees. They're at record levels. That's superheated Gulf of Mexico has been pumping moisture advection, moisture into the central plains and right through into the upper Midwest. So there are a couple of factors at work here that we're seeing these potentially near record dew points down in Iowa. I don't think it's all sensor issues, but it might be some.
CATHY WURZER: Wow. So when might we get some relief?
PAUL HUTTNER: Yeah, it's coming. It's going to be slow, though. So I think we're 97, 98 today in the Twin Cities. As I said, much cooler just north of the Twin Cities and through most of Central and Northern Minnesota.
Tomorrow, sunny, not quite as hot. Around 90. And then Friday, when I think you and I will be chatting out at the State Fair, which will be fun, 88 for the high. Should be in the 80s about the time we're on the air around 11:00 AM. And then the weekend looks great, Cathy. Cooler. Pleasantly cooler. 70s to around 80 this weekend.
CATHY WURZER: Does it usually get-- if my memory serves me, it usually gets pretty hot those first few days of the fair,
PAUL HUTTNER: Yeah, it certainly can, and it has in the past. By the way, I think Saturday through Tuesday will be the most comfortable days this year. So it looks great. I think we're going to see some big attendance numbers this weekend, Saturday and Sunday, highs in the 70s to low 80s.
But Minnesota DNR Climate Group has put out some pretty cool stats on the State Fair. The hottest ever was 104 back on September 10, 1931, and that year was the hottest year. The average high that year was 92.6 degrees.
But recently, in 2013, we had the most 90-degree days, six of them during the run of the fair. That was the third warmest State Fair. And just for the flip side of the coin, Cathy, the coldest day ever, can you imagine 52 degrees for a high at the fair, September 7 of 1911?
CATHY WURZER: That's not fun. It's the fair. You want to be that cold. All right. But before you go, what's on Climate Cast?
PAUL HUTTNER: Yeah. There's a backlog of renewable energy projects around the country. Wind and solar are trying to get on the grid. The process has been slow. The Federal Energy Regulatory Commission is coming up with some new regulations, try to speed that up. So we'll talk about that tomorrow on Climate Cast during All Things Considered.
CATHY WURZER: All right, Paul Huttner. And again, I'll see you Friday at 11:00 AM at the MPR booth.
PAUL HUTTNER: Looking forward to it. Thanks C.
CATHY WURZER: All right. That's our chief meteorologist, Paul Huttner.
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