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I'm not very familiar with Helsinki's geography, but how varied are the average highs and lows? Are they more or less uniform across the metro area?
That's not at all the case here. Especially the minimum temps. A combination of a massive UHI and Lake Michigan make the immediate city proper warmer than the suburbs
Right on the lake (literally)
MDW is 20km away
Streamwood about 40km way (just west of ORD )
The USA takes meteorology very seriously, we don't even have snowfall data and we are in bloody Scandinavia
I'm not very familiar with Helsinki's geography, but how varied are the average highs and lows? Are they more or less uniform across the metro area?
That's not at all the case here. Especially the minimum temps. A combination of a massive UHI and Lake Michigan make the immediate city proper warmer than the suburbs
The differences are smaller in Helsinki. The differences between the Kaisaniemi and airport stations are the max possible. The historical centre is on a windy cape and affected by UHI, while the airport is technically a rural station. As seen here: https://goo.gl/maps/jtfYY The red dot is the approximate location of the Kaisaniemi station and the airport is up north there. You can't miss it.
Helsinki is also like 10 times smaller than Chicago, so you quickly lose the UHI effect. The differences in elevation are small. Kaisaniemi is at 4 m asl and the airport at 51 m. The Kaisaniemi averages are representative for the centre only, while the airport station is more representable of the general conditions in the metro area, and is also the one usually used in the media.
The differences are smaller in Helsinki. The differences between the Kaisaniemi and airport stations are the max possible. The historical centre is on a windy cape and affected by UHI, while the airport is technically a rural station. As seen here: https://goo.gl/maps/jtfYY The red dot is the approximate location of the Kaisaniemi station and the airport is up north there. You can't miss it.
Helsinki is also like 10 times smaller than Chicago, so you quickly lose the UHI effect. The differences in elevation are small. Kaisaniemi is at 4 m asl and the airport at 51 m. The Kaisaniemi averages are representative for the centre only, while the airport station is more representable of the general conditions in the metro area, and is also the one usually used in the media.
Helsinki (the city) is 276 square miles, Chicago is 234 What city ranges are wikipedia using...
Edit: Silly me, they were taking into account water area too for the 'city' area
Yes, the land area of Helsinki is 82.5 sq mi. The Helsinki borders go all the way down to the international waters.
Wow, I didn't even know it was bigger than Stockholm, but then again, even Gothenburg is bigger than Stockholm with an area of 173 square miles... (5.6sq mi being water)
The differences are smaller in Helsinki. The differences between the Kaisaniemi and airport stations are the max possible. The historical centre is on a windy cape and affected by UHI, while the airport is technically a rural station. As seen here: https://goo.gl/maps/jtfYY The red dot is the approximate location of the Kaisaniemi station and the airport is up north there. You can't miss it.
Helsinki is also like 10 times smaller than Chicago, so you quickly lose the UHI effect. The differences in elevation are small. Kaisaniemi is at 4 m asl and the airport at 51 m. The Kaisaniemi averages are representative for the centre only, while the airport station is more representable of the general conditions in the metro area, and is also the one usually used in the media.
Thanks. I knew that Helsinki is much smaller than Chicagoland, but I would have thought that since it's next to a large body of water that there might be significant differences in parts of the area at least during certain times of the year.
^^
This analysis describes lake breezes as a summer benefit, I call it a summer buzz kill. Luckily now I live far enough away from the lakeshore only to be impacted by the strongest "northern fetch" lake winds mainly during the Spring.
I can't stress how much of an impact the Lake has on Chicago's climate. Inner city UHI+ a large body of water can keep the nightly minimum in all seasons
The stations with the lowest minimum temps on average are in the western and northern suburbs (away from the lake)
Barrington, which is a super affluent northern suburb is actually a bit "hilly" not much at all but enough to make it the coldest station in the metro area during the winter months (also quite cool in the summer).
An example of how our suburbs (especially west) can get much colder than the usually "lake insulated" stations during the winter. These temps were from Feb 2011
"The Helsinki urban heat island has made Kaisaniemi seem a warm weather observation station – which it is, on a larger scale. For example, it has one of Finland’s highest effective temperature sums in the growing season. On a smaller scale, however, Kaisaniemi stands out as a very cold place. The city streets, where people move, are considerably warmer. The Testbed observations can also be used to estimate the intensity of the Helsinki heat island by comparing city-centre data to those of a topographically comparable station located outside the centre at an equal distance from the sea. The station in the Roihupelto green area of the Radiation and Nuclear Safety Authority Finland constitutes a station comparable to that of Sörnäinen. In geographical terms, it represents the temperature conditions of sparsely built suburban areas. No observations could be made in Roihupelto in the summer months because the station was out of service, but the average temperature in the winter was 1.1° C lower than that of Sörnäinen. Since the urban heat island phenomenon is not quite as strong in Sörnäinen as the city centre, and since Roihupelto is not fully unbuilt, it is safe to assume that the temperature difference was larger than the 1.1° C observed.
The heat island phenomenon can also be studied by setting up an observation station, which corresponds to the geographical conditions of the centre of Helsinki, outside the city. Such a station is located in Santahamina, which is of a similar form and at a similar distance from the coast as the city centre. The place of measurement was chosen to represent the average elevation of Santahamina to ensure that any temperature difference between it and the city centre was caused purely by the heat island phenomenon, not by the topography or distance to the sea. Based on the results, the average temperature in 2012 of sparsely built areas outside the city centre was approximately 0.65° C lower than that of the large parks downtown (Kaisaniemi) and 1.1° C lower than that of built-up areas in the centre (Central Railway Station). This closely corresponds to the results obtained in, for example, the Helsinki Testbed project."
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What city ranges are wikipedia using...
Luckily now I live far enough away from the lakeshore only to be impacted by the strongest "northern fetch" lake winds mainly during the Spring.
