Is it summer yet?; frost advisory northern Minnesota Saturday night

Today is the start of meteorological summer!

The National Oceanic and Atmospheric Administration has this explanation of the meteorological seasons:

Meteorologists and climatologists break the seasons down into groupings of three months based on the annual temperature cycle as well as our calendar. We generally think of winter as the coldest time of the year and summer as the warmest time of the year, with spring and fall being the transition seasons, and that is what the meteorological seasons are based on. Meteorological spring includes March, April, and May; meteorological summer includes June, July, and August; meteorological fall includes September, October, and November; and meteorological winter includes December, January, and February.

NOAA's comparison of the meteorological seasons to the astronomical seasons can be found here.

Temperature trends

Many spots in the northern third of Minnesota, plus northwestern Wisconsin, will see Saturday highs in the 60s. Elsewhere in Minnesota and western Wisconsin, highs will be mainly around 70 to the lower 70s. Our average high temp is 74 degrees this time of year in the Twin Cities metro area.

It'll be chilly late Saturday night into early Sunday, and a frost advisory has been issued from 2 a.m. to 8 a.m. Sunday in parts of northern Minnesota:

The advisory does not include the Duluth area.

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3:30 p.m. Update

The National Weather Service has expanded the frost advisory to include more of northern Minnesota, including Duluth, from 2 a.m. to 8 a.m. Sunday.  Several northwestern Wisconsin counties have also been added to the advisory. In addition, portions of northern Minnesota that were in the initial frost advisory will now be in a freeze warning for that same time period:

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Sunday highs will be warmest southwest, and coolest to the northeast:

Twin Cities metro area highs are projected to reach the upper 70s Monday through Wednesday, followed by around 80 degrees on Thursday and Friday.

Wildfire smoke

Saturday morning satellite pictures show smoke from Canadian wildfires over much of central and southern Minnesota.  The wildfire smoke will filter our sunshine a bit today.

To see if the smoke will have any effect on our air quality at ground level, you can check the Minnesota Pollution Control Agency air quality readings and forecasts here.

Rain chances

Southeastern Minnesota could see some scattered showers this Saturday morning and the far southeast could see a shower chance early in the afternoon as well. Most of Minnesota will stay rain-free the remainder of this weekend.

As always, updated weather information can be heard on the Minnesota Public Radio Network, and you’ll also see updated weather info on the MPR News live weather blog.

Monday is looking dry. We could see some rain showers at times from Tuesday into Tuesday night. The National Oceanic and Atmospheric Administration’s Global Forecast System model shows the potential precipitation pattern from Tuesday through Wednesday morning:

The color chart to the right of the loop refers to the precipitation rate (mm per hour), not to the total amount of rain.

May recap

The month of May was cooler and wetter than normal in the Twin Cities (and much of Minnesota).

Although we hit 88 degrees at Minneapolis-St. Paul International Airport on Friday, the average temperature for the entire month of May was 3.5 degrees below normal in the Twin Cities.

Our May rainfall total of 6.68 inches at MSP airport was about double our long-term average May rainfall total:

Programming note

You can hear my live weather updates on Minnesota Public Radio at 7:49 a.m. Thursdays and Fridays, and at 7:35 a.m., 9:35 a.m. and 4:35 p.m. each Saturday and Sunday.