Except for the record tornado outbreak in southeast South Dakota on June 24th, it was a rather mild and non-extreme year in the tri-state area around Sioux Falls. Total precipitation at the Sioux Falls airport was 21.81 inches, 2.88 inches below normal. However, as is often the case, southern and eastern parts of the Sioux Falls area received more, with over 25 inches reported in 2003. The temperatures averaged out to 46.1 degrees for 2003, or 1.0 degree above the normal of 45.1 degrees.
The 2002-2003 winter was rather dry and mild, which has become more common in recent years. Only 1.40 inches precipitation and 16.8 inches snowfall occurred from November 2002 through March 2003, or 3.31 inches and 19.2 inches respectively below normal. March 2003 was the 5th driest March on record with only .22 inch precipitation. It was the normally less snowy months of October 2002 with 6.3 inches, and April 2003 with 9.0 inches, that helped to make a total of 32.1 inches for the 2002-2003 snow season.
2003 started fairly warm, culminating with record highs of 56 degrees and 57 degrees on January 7th and 8th respectively. It then cooled to more normal temperatures the rest of the winter. The lowest temperature of 2003 occurred on January 23rd with a low of -16 degrees. In February, there was one good snow of 5.7 inches preceded by some sleet and freezing rain. However, the biggest snow event of the year was on April 6-7th when there was 8.8 inches snowfall at the airport, but up to 11 inches in southwest Sioux Falls. The snow did not stick around as the temperatures warmed up and reached 85 degrees both on April 13th and 14th. Then there was a nice rain event of 1.44 inches on April 18th.
The weather was rather uneventful with somewhat below normal temperatures and precipitation through May and the first half of June. But then summer kicked in with higher temperatures, humidity, and then severe thunderstorms. The high point of the severe weather was the evening of June 24th, when tornado-producing severe thunderstorms pummeled southeast South Dakota. 67 tornadoes were documented in eastern South Dakota that evening, which tied a record for the most tornadoes in any state within a 24 hour period. Tornadoes occurred from south through west of Sioux Falls within 15 miles, with the more significant tornadoes from Parker to near Hartford. There was also very heavy rain and hail with these storms, with the west side of Sioux Falls receiving near 3 inches of needed rain.
There were also severe thunderstorms of note in early July. In the late evening of July 3rd, a squall line of thunderstorms blew through the tri-state area with up to 70 mph winds. Then in the late evening of July 4th thunderstorms brought hail up to golf-ball and winds up to 70 mph just north of Sioux Falls. On the night of July 7-8th, heavy rains up to 5 inches caused flash flooding in southern Turner County south of Sioux Falls. This was the last rainy spell for the rest of the summer as it turned very warm and dry in most areas. The warmest temperature of 2003 of 97 degrees was recorded on both August 16th and 17th.
By September a good widespread rain was much needed, and it occurred from September 9-11th with a total of 3.58 inches at Sioux Falls airport. The 2.63 inches on September 10th was a record for the date. Temperatures were above normal the rest of the year from October through December. Record highs were registered on October 18th with 84 degrees and on October 19th with 85 degrees. December was especially mild, averaging 7.2 degrees above normal for the month. Two good snows helped the moisture situation, with 5.1 inches on November 23rd and 8.5 inches on December 9th.
THE FOLLOWING TABLES GIVE A MONTH BY MONTH BREAKDOWN OF WEATHER IN 2003 AT THE SIOUX FALLS AIRPORT...
AVERAGE DEPARTURE EXTREMES MONTHLY MONTH MAX MIN MONTHLY FROM NORM HIGH LOW RECORDS JANUARY 27.2 8.0 17.6 PLUS 3.6 57 16B FEBRUARY 30.1 7.5 18.8 MINUS 2.0 52 9B MARCH 45.1 20.8 33.0 PLUS 0.4 78 12B 5TH DRIEST APRIL 59.4 36.3 47.9 PLUS 2.2 85 11 MAY 67.3 43.7 55.5 MINUS 2.3 81 33 JUNE 78.1 54.4 66.2 MINUS 1.3 91 44 JULY 84.3 61.7 73.0 ZERO 93 49 AUGUST 85.4 61.2 73.3 PLUS 2.5 97 47 SEPTEMBER 72.7 47.2 60.0 MINUS 0.9 93 32 OCTOBER 64.2 37.4 50.8 PLUS 2.8 85 22 NOVEMBER 41.2 22.6 31.9 PLUS 0.6 64 0 DECEMBER 32.8 18.3 25.5 PLUS 7.2 48 0 2003 57.3 34.9 46.1 PLUS 1.0 97 16B NORMAL YEAR 57.2 33.0 45.1
DEPARTURE DEPARTURE MAX WIND GUSTS... MONTH FROM NORM SNOWFALL FROM NORM DIRECTION/MPH/DATE JANUARY .30 MINUS .21 4.1 MINUS 3.3 NW 51 ON 9TH FEBRUARY .64 PLUS .13 6.3 PLUS 0.4 NW 51 ON 11TH MARCH .22 MINUS 1.59 4.6 MINUS 3.5 NW 47 ON 28TH APRIL 3.69 PLUS 1.04 9.0 PLUS 5.5 S 53 ON 15TH MAY 2.64 MINUS .75 0 NW 53 ON 30TH JUNE 3.54 PLUS .05 0 SW 52 ON 24TH JULY 1.64 MINUS 1.29 0 S 51 ON 3RD AUGUST 1.82 MINUS 1.19 0 NE 38 ON 5TH SEPTEMBER 4.74 PLUS 2.16 0 SE 47 ON 10TH OCTOBER .92 MINUS 1.01 0.1 MINUS 1.0 NW 46 ON 28TH NOVEMBER .59 MINUS .77 7.6 ZERO NW 55 ON 12TH DECEMBER 1.07 PLUS .55 13.4 PLUS 6.4 NW 45 ON 16TH 2003 21.81 MINUS 2.88 45.1 PLUS 4.5 NW 55 NOV 12TH RICHARD S. RYRHOLM/ CLIMATIC FOCAL POINT