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Category Archives: Seasons
When is the warmest day of the year?
As we move past mid-July, the climatologically warmest day of the year in Madison (i.e. the day with the highest average high temperature) is in our immediate wake.
Every 10 years the 30-year climatology is updated in the following way: In 1972, we used the 1941-1970 average as climatology. By 1982 we were using the 1951-1980 average as climatology. Currently, we are using the 1981-2010 average as climatology. Continue reading
Does Memorial Day or Labor Day have better weather?
A Memorial Day traditionally marks the beginning of the summer while Labor Day marks the end. People are bound to have their own recollections and opinions about which weekend more reliably delivers agreeable weather here in southern Wisconsin and those opinions can be colored by many non-meteorological influences.
If forced to opine on this question while sticking to strictly meteorological factors, we would suggest that Labor Day weekend’s weather is more reliably summerlike. The reason for this comes directly from the fact that Memorial Day comes as winter is ending and Labor Day as winter approaches. Continue reading
Why are there April showers?
As we head into the second half of April, recent weather has reminded us all of the old saying, “April showers bring May flowers.” The question, of course, is why does April bring the showers? First of all, is it … Continue reading
What is permafrost?
Permafrost is ground that is frozen for at least two years. It remains frozen all year and contains plant material that has not yet completely decomposed.
Permafrost is mostly located in polar regions, though it also occurs in some high mountain tops where it is called alpine permafrost. There is no permafrost in Madison, though our ground does freeze in most winters. Continue reading
Is water always present in the atmosphere?
Evidence of the presence of water in our atmosphere is ubiquitous. Water occurs in the Earth’s atmosphere in all three of its phases — solid (snow and ice), liquid (rain and dew) and gas (invisible water vapor).
As we begin to emerge from winter and enter spring, we may begin to see more dew on the ground and on the windshields of cars in the morning. The air nearly always holds some amount of water vapor. Dew is liquid water that condenses overnight onto objects when the air that contains the water vapor cools to a sufficiently low temperature. Continue reading
