National Weather Service United States Department of Commerce

SIOUX FALLS AREA
CLIMATIC SUMMARY
1997

 

By Richard Ryrholm
Climatic Focal Point
National Weather Service, Sioux Falls

 

...1997 STARTED OFF RATHER NASTY BUT IT GRADUALLY GOT BETTER...

 

1997 was overall a rather dry and cool year in the Sioux Falls area. Temperatures averaged out to 43.7 degrees in 1997 or 1.8 degrees below the normal of 45.5 degrees. Precipitation totaled 20.26 inches at Sioux Falls airport or 3.60 inches below the normal of 23.86. The lowest recorded temperature for 1997 was 19 below zero on January 28th and the highest temperature was 96 on June 28th.

The first half of 1997 was colder than normal but near normal in precipitation. January was dangerously cold at times with two blizzards...one from the 4th to the 5th and the worst one from the 9th to the 11th. Only 2 to 3 inches snowfall occurred in each blizzard but with the strong winds and existing snow cover visibilities were reduced to zero in open areas. The blizzard from the 9th to the 11th produced wind speeds up to 50 mph and wind chills to 80 below zero. A record low maximum temperature of 12 below zero occurred on the 10th. Another extreme wind chill event took place from the 15th to the 16th with wind chills as low as 70 below.

The big snow event of 1997 was from February 3rd to the 4th when 10.6 inches snowfall was measured at Sioux Falls airport. Some other areas around Sioux Falls reported 12 to 15 inches of fairly wet snow with this storm. March was an uneventful month and was the 5th driest March since records began in Sioux Falls in 1893. But April had the last hurrah of winter as seems to happen often in this part of the country. Rainfall of 1.07 inches at Sioux Falls on the 5th was followed on the 6th by up to 2 inches of snow and northwest winds gusting to 62 mph at the airport. Another dose of winter hit on the 10th with up to 5.5 inches snowfall in the area.

In addition flooding due mainly to snowmelt occurred on area rivers...lakes...and lowlands with most crests from April 3rd to the 9th. However a devastating flood was avoided in Sioux Falls due to the timely cold weather and relatively gradual spring snowmelt. Both April and May were well below normal in temperatures with April 1997 the 6th coldest April on record and May 1997 the 2nd coldest May on record. This made the spring period of March through May 1997 the 7th coldest spring on record. Record low temperatures occurred on the following days in April and May...8 on April 8th...10 on April 9th...21 on May 1st...24 on May 13th...and 27 tied the record on May 15th. Record low maxes occurred within a 5 day period in early April...28 on April 6th...23 on April 8th...31 on April 9th...and 29 on April 10th.

Precipitation was adequate...timely...and near to somewhat above normal from April through July...the prime time for needed crop moisture in the area. The rest of the year was rather dry but with overall pleasant temperatures.

Significant thunderstorms in the area included...

1. On June 20th...before sunrise around 5 am over an inch of rain occurred in southern Sioux Falls along with reports of 3/4 inch diameter hail.

2. On June 29th...thunderstorms dumped 2.68 inches of rain within several hours at the Sioux Falls airport for the heaviest precipitation event in 1997.

3. On July 13th...large hail fell in area about 5 miles wide and at least 15 miles long from west to northeast of Sioux Falls. Severe damage to vehicles occurred...including several which sustained total damage. Homes and other buildings had windows broken and siding and roofs severely damaged. At least one satellite dish was damaged at the EROS Data Center and the building sustained other damage as well. Crops were severely damaged with many acres totally destroyed.

4. On September 8th...at 220 pm thunderstorm winds gusting to 66 mph blew in some car windows and caused tree damage in Sioux Falls.

5. On October 8th...at 7 pm thunderstorms produced wind gusts to 60 mph and localized nickel size hail in Sioux Falls.

THE FOLLOWING TABLES GIVE A MONTH BY MONTH BREAKDOWN OF WEATHER IN 1997 AT THE SIOUX FALLS AIRPORT...

TEMPERATURES

TEMPERATURES
                 AVERAGE             DEPARTURE  EXTREMES    MONTHLY
 MONTH          MAX   MIN   MONTHLY  FROM NORM  HIGH LOW    RECORDS

JANUARY        18.0  B0.8      8.6   MINUS 5.2   43  19B
FEBRUARY       27.1   8.7     17.9   MINUS 1.8   41  14B
MARCH          40.7  20.4     30.6   MINUS 1.9   74   6B    5TH DRIEST 
APRIL          52.0  29.1     40.6   MINUS 6.3   75   8     6TH COLDEST 
MAY            64.0  38.9     51.5   MINUS 6.9   85  21     2ND COLDEST 
JUNE           80.9  56.7     68.8    PLUS 0.5   96  46
JULY           81.9  62.8     72.4   MINUS 1.9   93  45
AUGUST         79.7  58.0     68.9   MINUS 2.5   90  48
SEPTEMBER      75.1  49.7     62.4    PLUS 1.5   88  32
OCTOBER        62.2  36.5     49.4    PLUS 0.8   89  12
NOVEMBER       37.0  18.8     27.9   MINUS 5.1   56   2B
DECEMBER       34.0  18.2     26.1    PLUS 7.8   52   4

 1997          54.4  33.1     43.7   MINUS 1.8   96  19B

NORMAL YEAR    56.8  34.2     45.5

PRECIPITATION (INCHES) AND WINDS

DEPARTURE             DEPARTURE    MAX WIND GUSTS... 
   MONTH           FROM NORM   SNOWFALL  FROM NORM   DIRECTION/MPH/DATE 

JANUARY     .41   MINUS  .10      8.8     PLUS 2.1      NW 47 ON 10TH 
FEBRUARY   1.39    PLUS  .75     16.5     PLUS 8.8      NW 37 ON 18TH 
MARCH       .23   MINUS 1.41      1.3    MINUS 6.7      NW 46 ON 21ST 
APRIL      2.43   MINUS  .09      6.0     PLUS 3.8      NW 62 ON 6TH 
MAY        3.58    PLUS  .55       0                     S 41 ON 17TH 
JUNE       3.77    PLUS  .37       0                     S 36 ON 23RD 
JULY       2.94    PLUS  .26       0                    NW 48 ON 2ND 
AUGUST     1.58   MINUS 1.27       0                     S 37 ON 29TH 
SEPTEMBER  1.59   MINUS 1.43       0                     N 49 ON 8TH 
OCTOBER    1.75   MINUS  .03      0.4    MINUS 0.2       S 52 ON 8TH 
NOVEMBER    .35   MINUS  .74      5.0    MINUS 0.1      NW 49 ON 2ND 
DECEMBER    .24   MINUS  .46      3.3    MINUS 4.5       N 51 ON 30TH

 1997     20.26   MINUS 3.60     41.3     PLUS 3.2      NW 62 APR 6TH

NOTE...ALSO MAX WIND GUST IN OCTOBER OF 52 MPH OUT OF WEST ON THE 13TH


RICHARD S. RYRHOLM/ CLIMATIC FOCAL POINT