Is Lake Superior's climatic effect greater on Grand Marais than Duluth or Grand Portage? (Moose Lake: house)

[Musikälskaren]

Good Morning Minnesota! I was surfing Wikipedia and reading about different places when I noticed that Grand Marais has warmer Winter averages and cooler Summer averages than Duluth or even Grand Portage, assuming that Wikipedia is correct. I Googled because I'm rather curious as to why that may be but I couldn't find much of anything that explained it. It's probably out there and I just failed to locate it but I wanted to see if any of my City-Data friends may have any knowledge or insight as to why Grand Marais may have a slightly more pronounced lake effect influenced climate than Duluth or Grand Portage? At any rate, it's interesting and cool (especially in Summer lol!). As we all know, all of these places have obvious lake influenced climates and they're quite awesome in my opinion! Also, this discussion doesn't have to be limited to those three cities, feel free to mention any other places in or near the North Shore area. Thank you in advance!

[Unsettomati]

Originally Posted by Musikälskaren

Good Morning Minnesota! I was surfing Wikipedia and reading about different places when I noticed that Grand Marais has warmer Winter averages and cooler Summer averages than Duluth or even Grand Portage, assuming that Wikipedia is correct. I Googled because I'm rather curious as to why that may be but I couldn't find much of anything that explained it. It's probably out there and I just failed to locate it but I wanted to see if any of my City-Data friends may have any knowledge or insight as to why Grand Marais may have a slightly more pronounced lake effect influenced climate than Duluth or Grand Portage? At any rate, it's interesting and cool (especially in Summer lol!). As we all know, all of these places have obvious lake influenced climates and they're quite awesome in my opinion! Also, this discussion doesn't have to be limited to those three cities, feel free to mention any other places in or near the North Shore area. Thank you in advance!

Anecdotally, twice in the past two weeks I've happened to watch the evening Twin Cities newscast (I rarely do this - I only use my television for streaming and DVDs, but happened to see it once at work and once at my in-laws' cabin). Anyway, the usual statewide high-temperature weather map was displayed. Each time, highs statewide were in the 70s and 80s - except for Grand Marais, mired in the mid-50s on both occasions. Of course, I realize that two viewings is a very small sample size.

I doubt there's much available climate data on Grand Portage - the unincorporated town and the Indian Reservation barely top 1000 people combined. There's just not much there.

As for Grand Marais compared to Duluth, the positioning of the weather stations might be a factor. Grand Marais is so small that the weather station might be very close to the lake, whereas Duluth is large enough that even the "down the hill" station may be comparatively far inland. And remember that much of Duluth is well up the hill (actually, the slope leading to the generally higher elevation of northern Minnesota), or on top of it. When I lived in Duluth (I presume it is still that way) the local news gave two temperatures: that downtown (by the lake) and that up on the hill (at the airport). The lakeside temperature was almost always more moderate (cooler in the summer and "warmer by the lake", as the saying goes, in the winter). So the effect of the lake on the two cities might simply appear to differ just because of where meteorological readings are taken in each city. Something to consider.

[Musikälskaren]

Originally Posted by Unsettomati

Anecdotally, twice in the past two weeks I've happened to watch the evening Twin Cities newscast (I rarely do this - I only use my television for streaming and DVDs, but happened to see it once at work and once at my in-laws' cabin). Anyway, the usual statewide high-temperature weather map was displayed. Each time, highs statewide were in the 70s and 80s - except for Grand Marais, mired in the mid-50s on both occasions. Of course, I realize that two viewings is a very small sample size.

I doubt there's much available climate data on Grand Portage - the unincorporated town and the Indian Reservation barely top 1000 people combined. There's just not much there.

As for Grand Marais compared to Duluth, the positioning of the weather stations might be a factor. Grand Marais is so small that the weather station might be very close to the lake, whereas Duluth is large enough that even the "down the hill" station may be comparatively far inland. And remember that much of Duluth is well up the hill (actually, the slope leading to the generally higher elevation of northern Minnesota), or on top of it. When I lived in Duluth (I presume it is still that way) the local news gave two temperatures: that downtown (by the lake) and that up on the hill (at the airport). The lakeside temperature was almost always more moderate (cooler in the summer and "warmer by the lake", as the saying goes, in the winter). So the effect of the lake on the two cities might simply appear to differ just because of where meteorological readings are taken in each city. Something to consider.

That makes sense, thank you for your reply! I don't know why but this stuff is so fascinating to me!

[Kamsack]

Hi I am a meterologist in Grand Forks ND.... I would say the climate of each place is impacted by the lake.

For Duluth as the previous poster said you have two sections weather wise for Duluth -- the top of the hill where the airport is and the smaller airport downtown along the lakefront where official record keeping started and still does. For the Duluth Airport temps (which are often posted on TV maps and is the commercial airport KDLH you will have lesser impacts with warmer summer temps and colder winter temps.....nighttime temps often are colder as well. At the lakefront downtown you have a considerably cooler summer temp but a bit warmer winter temp due to "warmer" lake waters (that is until the harbor freezes over and then the influence is less downtown). Also winter nighttime temps would be considerably warmer mainly due to city location at the lakefront vs the slightly less urban area around the airport. Northeast winds impact the city of Duluth and bring fog inland quite often in the spring season before the lake warms up...and in winter storms winds northeast to east winds can be very strong off the lake and enhance snowfall/wind speeds for downtown Duluth. These impacts of winds and fog can extend pretty far inland in certain circumstances.

For the other two locations...both are right on the lake and smaller and thus dont have the over the hill vs lakefront issues. Times when you will notice lake influence is when there are south winds.... South winds can bring warm air into the area inland but in areas on the north shore of the lake such as Grand Portage and Grand Marais the wind is right off the cool lake waters. You need a northwest or west wind to warm these locations up in the summer. Fog and low clouds can occur along the lakefront from Duluth up to Grand Marais and Thunder Bay Ont esp in spring-early summer when lake and air temp differences are maximized.

[tvdxer]

In the case of Duluth, it's generally warmer in the winter and cooler in the summer at the harbor than at the airport. However, the lake still has a strong influence at the airport, and sometimes a weaker one all the way south to about Moose Lake or further. Especially in the months of May and June, a cool mist will hang over the lower-situated neighborhoods, keeping the temperature at a smooth 40-55F, while just a mile inland it will be sunny and 65-86+F.

This fog or mist also has the effect of amplifying the odor of the water treatment (sewage) plant, sometimes to an almost unbearable degree. I remember at least two days in the past when it was so intense at the 27th Ave W and I-35 area that you could almost taste the nasty waste.

Interestingly, sometimes in the summer the opposite can happen, especially during late-summer heat waves. Check out this:

Weather History for Duluth, MN | Weather Underground

vs.

Weather History for Duluth Sky Harbor, MN | Weather Underground .

Note the differences in monthly maximum temperatures (96 vs. 91), dewpoints (an astonishing 81 vs. 73), and average monthly lows (60 vs 56). I remember that day...it was oppressive enough well-inland, but it was pure equatorial weather going across the bridge, with air about as thick as a jungle.

The terrain also makes daily reception of WIMI 99.7 "The Storm", Ironwood, MI, possible away from the antenna farm. Further up the shore stations from the Upper Peninsula once dominated the FM dial and still have a major presence there (hence WIMI's weather reports' include a "North Shore of Minnesota" forecast).

[Beenaroundabit]

For the other two locations...both are right on the lake and smaller and thus dont have the over the hill vs lakefront issues.

I think this is the key.

I have a Duluth address, but live about 7 miles North of the city, on the lake. We look at the city weather forecast and start subtracting, because it is usually a good 10 degrees cooler at my house than it is downtown. And up on "the hill," the difference can be even greater.

[Musikälskaren]

A lot of great answers with great information and I appreciate each and every post! Thank you guys and keep them coming! I can't wait to visit the North Shore again!

[Unsettomati]

Originally Posted by Unsettomati

Anecdotally, twice in the past two weeks I've happened to watch the evening Twin Cities newscast (I rarely do this - I only use my television for streaming and DVDs, but happened to see it once at work and once at my in-laws' cabin). Anyway, the usual statewide high-temperature weather map was displayed. Each time, highs statewide were in the 70s and 80s - except for Grand Marais, mired in the mid-50s on both occasions. Of course, I realize that two viewings is a very small sample size.

I doubt there's much available climate data on Grand Portage - the unincorporated town and the Indian Reservation barely top 1000 people combined. There's just not much there.

As for Grand Marais compared to Duluth, the positioning of the weather stations might be a factor. Grand Marais is so small that the weather station might be very close to the lake, whereas Duluth is large enough that even the "down the hill" station may be comparatively far inland. And remember that much of Duluth is well up the hill (actually, the slope leading to the generally higher elevation of northern Minnesota), or on top of it. When I lived in Duluth (I presume it is still that way) the local news gave two temperatures: that downtown (by the lake) and that up on the hill (at the airport). The lakeside temperature was almost always more moderate (cooler in the summer and "warmer by the lake", as the saying goes, in the winter). So the effect of the lake on the two cities might simply appear to differ just because of where meteorological readings are taken in each city. Something to consider.

Another example of Grand Marais being affected by the big lake:

Yesterday (Friday) morning I was listening to the weather on MPR. After running through a few current temperatures at different stations across the state, it was mentioned that only one station was reporting a temperature above the 30s - Grand Marais, coming in at a 'toasty' 47F.

[ryankong2010]

interested