Climate
In
winter, the average temperature at Ottertail
and Fergus Falls is 11 degrees F. The average
daily minimum temperature is 0 degrees at
Ottertail and 1 degree at Fergus Falls.
The lowest temperature on record at Ottertail,
which occurred on February 3, 1982, is -41
degrees. The lowest temperature on record
at Fergus Falls, which occurred on February
5, 1982, is -40 degrees.
In summer, the average temperature is 69
degrees at Ottertail and 68 degrees at Fergus
Falls. The average daily maximum temperature
is 80 degrees at both recording stations.
The highest temperature at Ottertail, which
occurred on July 27, 1988, is 102 degrees.
The highest temperature at Fergus Falls,
which occurred on August 16, 1988, also
is 102 degrees.
Growing degree days are equivalent to “heat
units.” During the month, growing
degree days accumulate by the amount that
the average temperature each day exceeds
a base temperature (40 degrees F). The normal
monthly accumulation is used to schedule
single or successive plantings of a crop
between the last freeze in spring and the
first freeze in fall.
The total annual precipitation at Ottertail
is 26.56 inches. Of this, 19.45 inches,
or about 73 percent, usually falls in April
through September. The total annual precipitation
at Fergus Falls is 23.25 inches. Of this,
17.46 inches, or 75 percent, usually falls
in April through September. The growing
season for most crops falls within this
period. The heaviest 1-day rainfall during
the period of record was 4.4 inches at Ottertail
on June 19, 1979, and 4.3 inches at Fergus
Falls on August 7, 1992. Thunderstorms occur
on about 32 days each year, and most occur
in July.
The average seasonal snowfall is 49.9 inches
at Ottertail and 40.3 inches at Fergus Falls.
The greatest snow depth at any one time
during the period of record was 34 inches
at Ottertail and 27 inches at Fergus Falls.
The heaviest 1-day snowfall on record was
14 inches at Ottertail and 12 inches at
Fergus Falls.
The average relative humidity in midafternoon
is about 62 percent. Humidity is higher
at night, and the average at dawn is about
81 percent.
The prevailing wind is from the south-southeast.
Average windspeed is highest, 14 miles per
hour, in April.
