1997 Sioux City Area Climate Summary

SIOUX CITY AREA
CLIMATIC SUMMARY
1997

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

...DRY YEAR OVERALL AT SIOUX CITY IN 1997 BUT NOT AS COOL AS 1996...

The average temperature at Sioux City in 1997 was 47.5 degrees compared to a normal of 48.5 degrees. Precipitation totaled only 18.45 inches at Sioux City airport or 7.41 inches below the normal of 25.86 inches. However near normal precipitation occurred in the months of April through June which helped to get area crops established.

January was rather cold with a couple of blizzards...one from the 4th to the 5th and the more severe one from the 9th to the 10th when there was 2.9 inches snowfall...wind gusts to 56 mph...and wind chills as low as 70 below zero. The biggest snowfall of the year was from February 3rd to the 4th when 7.7 inches was measured at the airport but up to 12 inches was reported in Sioux City itself. The next big weather event was on April 5th to the 6th. Rainfall of 1.10 inches occurred on April 5th followed on April 6th by westerly winds gusting to 60 mph and a little snow and blowing snow. There were 3 days in a row of record low maximums from the 9th to the 11th with highs of 32...31...and 29 respectively. Some flooding of area rivers also occurred mainly due to upstream snowmelt from March through early may.

A very rare temperature event occurred on May 16th. The morning low temperature of 33 degrees broke the old record low of 35. In the afternoon the high of 91 tied the record high for the same date. The heaviest rainfall event of 1997 at Sioux City airport was 1.44 inches on May 23rd.

April and may were well below normal in temperatures but the period from June through October was basically near normal. Some record high temperatures were broken in October with record highs of 94 on the 2nd and 91 on the 6th. Record high minimums occurred on October 7th with a 67 breaking the old record of 63 and on October 11th with a 66 over the old record of 64 for the date. There was a welcome flip/flop in temperatures from November to December with November well below normal and December well above normal making for a pleasant holiday season.

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

TEMPERATURES

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

JANUARY        23.6   5.5     14.6   MINUS 3.1   47  13B
FEBRUARY       32.5  17.0     24.8    PLUS 1.2   49   3B
MARCH          50.0  25.9     38.0    PLUS 2.2   79   8
APRIL          54.3  31.2     42.8   MINUS 7.4   79  14     4TH COLDEST 
MAY            68.4  42.5     55.5   MINUS 6.1   91  25
JUNE           85.1  58.5     71.8    PLUS 1.0   95  48
JULY           84.3  63.8     74.1   MINUS 1.6   95  48
AUGUST         82.4  58.9     70.7   MINUS 2.1   93  47     5TH DRIEST 
SEPTEMBER      78.6  51.0     64.8    PLUS 1.4   93  32
OCTOBER        66.3  38.5     52.4    PLUS 0.6   94  15
NOVEMBER       41.8  22.9     32.4   MINUS 4.0   60   0
DECEMBER       36.4  20.6     28.5    PLUS 6.7   56   7

 1997          58.6  36.4     47.5   MINUS 1.0   95  13B

NORMAL YEAR    59.2  37.7     48.5

PRECIPITATION (INCHES) AND WINDS

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

JANUARY     .35   MINUS  .20      6.2   MINUS  0.2      NW 56 ON 10TH 
FEBRUARY   1.01    PLUS  .30     10.6    PLUS  4.9      NW 39 ON 22ND 
MARCH       .46   MINUS 1.50      1.6   MINUS  5.9      NW 49 ON 21ST 
APRIL      3.07    PLUS  .73     11.5    PLUS 10.2       W 59 ON 6TH 
MAY        3.71    PLUS  .04       0                    NW 49 ON 11TH 
JUNE       3.09   MINUS  .62       0                     N 40 ON 20TH 
JULY       1.94   MINUS 1.33       0                    NW 51 ON 13TH 
AUGUST      .63   MINUS 2.34       0                    SW 54 ON 14TH 
SEPTEMBER  2.43   MINUS  .45       0                    NW 48 ON 27TH 
OCTOBER    1.29   MINUS  .65      0.3   MINUS  0.6       W 45 ON 13TH 
NOVEMBER    .26   MINUS  .82      0.9   MINUS  2.4      NW 59 ON 2ND 
DECEMBER    .21   MINUS  .57      1.6   MINUS  5.1       N 54 ON 30TH

 1997     18.45   MINUS 7.41     32.7     PLUS 0.9         59 APR 6TH
                                                              NOV 2ND

 
RICHARD S. RYRHOLM...CLIMATIC FOCAL POINT