SUBJECT: September 2002 Fourth Wettest on Record Saint Cloud September 2002 weather summary  

FROM: Bob Weisman

Earth Sciences, St. Cloud State University

The rains continued in Saint Cloud during September 2002. According to the official statistics from the Saint Cloud Regional Airport, the September rainfall totaled 6.67 inches. This makes September 2002 the fourth rainiest September in Saint Cloud recorded history, a time period that spans 111 years. The rainfall was more than double the normal September total of 2.93 inches and was the rainiest September since 1985 when 9.48 inches fell. The rainiest September in Saint Cloud recorded history was 1926 when 10.72 inches of rain was recorded.

The wet September continues the heavy rain that began, in earnest during June. The rainfall for the period of June 1 through September 30 is 22.30 inches, the 6th highest total in Saint Cloud records. This total is nearly 8 inches above normal. For comparison, the average annual Saint Cloud rainfall is 27.43 inches, so we have had more than 80% of a normal yearís rainfall during the past four months. The growing season (April 1 through September 30) total rainfall is now 27.73 inches, more than 7 1/2 inches above normal and the eighth highest total in Saint Cloud recorded history. The rainiest growing season through September was in 1986 when 31.17 inches fell. Another relatively recent rainy year was in 1985 when 28.77 inches fell, ranking fifth in Saint Cloud records.

About two-thirds of the rainfall during the month occurred on the night of September 5-6 when 4.39 inches of rain fell. This rainfall was the fifth heaviest 24-hour rainfall in Saint Cloud Airport history and the second heaviest 24-hour September rainfall, ranking only behind September 8-9, 1985 (see table below). The rainfall broke daily rainfall records for both September 5 (2.69 inches) and September 6 (0.99 inches). It was also the heaviest 24-hour rainfall recorded at Saint Cloud State University with a total of 4.48 inches measured and the third event in the Top 5 this year (see table below). The SCSU rainfall total since April 1 now stands at over 35 inches of rain.

These conditions have contrasted severely with the previous two warm seasons. In both 2000 and 2001, the June through September rainfall totaled around eight and a half inches, the 7th and 10th lowest rainfall totals on record. Grass and brush fires were common during both September and October due to the dry conditions the past two years.

September 2002 was a very warm month, but a month of extreme contrast. The first 12 days of September produced a daily average of 70.0 degrees, warmer than any September record if it would have held up. The coolest high temperature during this period was 74 degrees and Saint Cloud hit 91 degrees on the 8th, the 9th 90-degree of the year and the first since July. Even through September 18th, the average temperature was 67.5 degrees, which would have been warm enough to set a new record for September (the warmest September on record was in 1931 with an average temperature of 66.5 degrees). However, thatís when the Canadian Express hit. Over the last 12 days of the month, the high temperature only broke 60 degrees 5 times and there were two days with frost. The average temperature of the last 12 days was 51.7 degrees, a temperature that would have tied 1993 for the second coldest September on record. Overall, the September 2002 finished with an average temperature of 61.2 degrees, 3.8 degrees above normal. The month tied 1882, 1937, and 1963 for the 26th warmest September out of 122 years on record. However, this is only the second year in the past 40 years with an average September temperature of at least 61 degrees (September 1998 was the only other year this warm with an average temperature of 62.9 degrees, 14th warmest on record).

The frost on September 24 was only two days earlier than average. However, the late frost in May gave us a season between frosts that was 8 days less than normal.


SUMMARY FOR SEPTEMBER 2002             SEP 2002         NORMAL
Temperature (OF)
Average high temperature               72.1             69.0
Average low temperature                50.2             45.7
Average temperature                    61.2             57.4
Warmest high for this month            88 on the 5th
Coolest high for this month            55 on the 14th
Mildest low for this month             66 on the 6th
Coldest low for this month             28 on the 25th

Precipitation (in)
September                              6.67*              2.93    (SCSU: 7.37 in)
Greatest in 24 hours (Sept 2002)       4.39 on the 5th-6th%
Daily records broken                   2.72 on the 5th (old record: 2.69 in 1958)
                                       1.67 on the 6th (old record: 0.99 in 1948)

Total Precipitation: June-September   22.30                 14.37
Total Growing Season Precip (Apr-Sept)27.72                 19.98

*4th wettest September on record
%5th highest 24-hour rainfall on record
Saint Cloud State University Apr 1-Sept 30, 2002   35.03                    

GROWING SEASON STATISTICS
Temperature cutoff        Last day in spring   First day in fall    Number of days
32 degrees                   
2002                      May 20                  Sept 24               134
normal                    May 10                  Sept 26               142

Saint Cloud September Precipitation
        30-year Average = 2.93 in

Precipitation (in)       Year 
10.72                    1926
 9.48                    1985
 7.12                    1900
 6.67                    2002    4th highest total on record
 6.60                    1929
 6.55                    1983 
 6.49                    1914
 6.28                    1986
 6.12                    1934
 6.10                    1921

Saint Cloud Precipitation June 1- September 30
                     110-year Average = 14.37 in

Precipitation (in)       Year 
26.92                    1926
26.92                    1897
23.17                    1905
23.06                    1986
22.73                    1900
22.31                    2002  6th highest total on record
22.13                    1985
21.76                    1983
20.84                    1957
20.75                    1990

Saint Cloud Growing Season Precipitation (April 1- September 30)
                     110-year Average = 19.98 in

Precipitation (in)       Year 
31.17                    1986
30.90                    1965
30.70                    1905
29.76                    1897
28.83                    1903
28.77                    1985
27.98                    1926
27.72                    2002    8th highest total on record
27.17                    1990
26.73                    1912


HEAVIEST 24-HOUR RAINFALL TOTALS IN SAINT CLOUD HISTORY (AIRPORT)

AMOUNT (in)		        DATE
5.37				8-9 September 1985
4.80				2 July 1903
4.62				3-4 August 1956
4.50				6 July 1897
4.39				5-6 September 2002
4.12				19 August 1935
3.90				24 August 1895
3.74				22-23 April 2001
3.59				27 August 1960


HEAVIEST DAILY RAINFALL TOTALS IN SCSU HISTORY (1991-2002)

AMOUNT (in)		        DATE
4.48				5-6 September 2002
4.40				25-26 August 1995
4.29				10 July 2002
3.83				23 April 2001
3.63				3-4 August 2002
2.57				2 August 1997
2.37				7 September 1991
2.35				19 August 1997
2.25				25 July 1997
2.16				16 June 1994
2.07				26 August 1993


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Last modified: October 1, 2002