Have ya noticed it's been kinda cold lately?

The following question was posed to the State Climatology Office recently. We thought the question and the answer might be of general interest. Thank you to Mr. Folkman for the question.

Dear State Climatology Office,

Its been my non-quantified observation that the upper midwest (including 
Minnesota) has been in the grips of a generally artic-polar climatic flow over 
the last 1.5 to 3.0 years. Specifically, Its been my general observation that 
Minnesota's average monthly temperature has been below "normal" for a 
significantly high percentage of months (65%-75%  or more ???) over the last 
several years. This seems especially true for day-time high temperatures. 
Furthermore, I would also venture a guess that over the last 1, 2, or 3 year 
period, the number of colder than average days have greatly exceeded the number 
of above average days.

Question: Are my general observations close to reality, or am I simply becoming 
weary of our current long winter. 

Any information or observations that you can provide would be greatly 
appreciated.

Thank You

Sincerely,

Gordon Folkman

Hello Gordon,

Your observations are well founded. The summary below was prepared by Jim Zandlo,
the State Climatologist.

Greg Spoden
State Climatology Office

Recent monthly departures from normal temperature for Minneapolis-St.Paul were

      Jan  Feb  Mar  Apr  May  Jun  Jul  Aug  Sep  Oct  Nov  Dec   Ann
1994 -7.4 -4.7  3.7 -0.5  2.2  1.7 -3.5 -3.1  3.8  3.4  4.8  6.6   0.6
1995  6.7  1.4  4.0 -4.2 -1.6  3.0 -0.5  4.2 -0.3 -0.2 -5.8  1.2   0.7
1996 -1.6  0.1 -5.7 -5.0 -2.9 -0.8 -3.6    0  1.7    0 -7.8 -4.2  -2.4
1997 -1.5  2.0    . March 1997 is running quite cold as of the 18th.

The cold core of winter (Jan-Feb) and core of summer 1994 (Jul-Aug) stand out.
Also the 'hesitant' springs (cold Apr) and early cold (cold Nov) in both 1995
and 1996 are noteable. The fall-winter-spring of 1995-1996 set the record for
the longest stretch between 60 degree days (176). As for whole years, however,
1996 certainly WAS cold but the other years actually came out slightly warm overall.
Note that we haven't had a significantly warm month since Aug 1995. (If you would
like to think of these departures in more precise statistical terms, the standard
deviation for monthly temperature ranges from 2-3 for mid-summer, Jun-Aug to
about 6 for mid winter, Dec-Feb with other months having values between those
two extremes.)

As for departures from normal of the daily high temperatures, I don't have departures
from normal for just the highs. However, one commonly used measure of summer heat is
the number of days above 90 which averages about 15 days per year. Using that measure,
1994 with 4 and 1996 with 8 days were cool while 1995 was near normal with 18 days.

Cold in the late spring or early winter has the effect of prolonging winter
(a significant psychological disadvantage for most of us). In fact, last year the
fishing season (2nd weekend in May) was delayed in some areas due to ice on the lakes.

If you care to examine daily temperatures yourself, we have MSP data online back
to August 1995 at http://climate.umn.edu/doc/journal/prelim_lcd_msp.html
Older data is published by NOAA in 'Local Climatological Data'.

Return to the Climate Journal