SUBJECT: Was it that hot, or have we become wimps?
         July 1999 St. Cloud weather summary

    July 1999 weather will be seared into our memories for a while, especially
after the heat and high dew points of the final 10 days of the month. However,
was it really one of the worst ever?
    The statistics show that the average St. Cloud airport temperature for
July 1999 was 2.5 degrees above normal. Both the average high of 85.2 degrees
and the average low of nearly 60 degrees were about the same amount above
normal. This makes this July the warmest in the 1990's, but July 1989 was
slightly warmer (avg temp: 72.7 deg) and July 1988, the most searing year
of the 1986-1989 drought, was much hotter with an average temperature of
74.6 deg (avg high: 89.6; avg low: 59.5). To put this into even more 
perspective, July 1989 only ranks as the 10th hottest July on record in St.
     There were 9 days with a high of at least 90 degrees during July 1999
in St. Cloud, but only July 22-25 technically met the definition of a
heat wave (3 days of at least 90 degree highs). This was the first such
streak since 1995. The heat and oppressive humidity during the last week
of July 1999 did not technically qualify as a heat wave in St. Cloud
since there were only two 90 degree days. The 9 days with highs of at least
90 marks the most since July 1988 when there were 13 such days. The 11 90-degree
days for this summer thus far equal the normal number of 90-degree days for the
entire year.
      The 97-degree high on July 25 marked the warmest high temperature 
recorded in St. Cloud since July 13, 1995. The 98-degree high temperature
on the 30th of this year was the hottest day since July 3, 1990 when the
temperature hit 101. Add in the 80-degree dew point and the heat index reached
118 degrees, which would have been a record heat index for Minneapolis (highest
ever was 116 degrees). However, this statistic has only been kept for the
past 15 years.
      What these statistics really tell us is how cool the summers
of the 1990's have been rather than how extreme the weather has been during the
past month. The temperatures were warmer during both 1988 and 1989, the worst
of the late 1980's drought years. We have only had one previous year during
the 1990's (1995) which has had a significantly warmer than normal summer.
Also, the decade of the 1990's so far has had the coolest summers of
any decade in St. Cloud records. 
      The heat and humidity wave of last month has had devastating effects
nationwide with almost 200 heat-related deaths. However, dew points were
higher in Iowa and extreme southern Minnesota during the heat and humidity
wave of mid-July 1995 which killed nearly 600 people in Chicago and Milwaukee
alone. Still, it illustrates the point that heat is still the number one
weather-related cause of death in the United States. Moreover, since most
deaths and injuries are preventable, it illustrates our ignorance about
the problem.
       Finally, there have been many more severe heat waves and droughts
in St. Cloud (and nationwide) than what we experienced last week. The
worst is still July 5-18, 1936 during which St. Cloud had an AVERAGE
high temperature of 101.6 including record highs for 10 straight days,
all between 99 and 107.
       The rainfall total for July 1999 was pushed above normal by the 
thunderstorms which ended the oppressive heat on the 30th. However,
this doesn't account for the stress the persistent warm temperatures
put on local crops and lawns. The other part of the water balance
is evaporation which normally exceeds precipitation during the summer
and is even higher during hot periods.
       I estimated the evaporation in St. Cloud to be 4.81 inches in July,
almost an inch higher than the rainfall. This estimation doesn't include
the effects of wind on evaporation and also doesn't account for usage
by plants and ground water seepage. However, it does show that slightly
above normal rainfall isn't enough to cancel out the loss, especially
during the summer when water usage is high.

JULY STATISTICS                  JULY 1999              NORMAL
Average high temp                  85.2                  82.6
Average low temp                   59.9                  57.6
Average temp                       72.6                  70.1
Hottest high temp for the month   98 on the 30th
Coolest high temp for the month   75 on the  9th
Warmest low temp for the month    77 on the  4th (new record; see below)
Coolest low temp for the month    50 on the 11th,17th

Days with highs of at least 90     9                      4.7
Total for season                  11                     10.7

Daily record warm low:            77 on the 4th (old record: 74 in 1902)
Daily max precip:               1.22 on the 30th (old record: 1.10 in 1965)

Total for month                   3.86                   3.11
Maximum daily amount              1.22 on the 30th (broke record; see above)
Bob Weisman, Meteorology Professor	SUPERVISOR: Shirley (age 7)
Earth Sciences Department		PHONE: (320) 255-3247 (V)
MS 48                                          (800) 627-3529 (TTY via
Saint Cloud State University                        Minnesota Relay Service)
720 4th Avenue South			FAX:   (320) 255-4262
Saint Cloud, Minnesota 56301-4498  	EMAIL: scsweisman@tigger.


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Last modified: August 3, 1999