SIOUX CITY AREA
CLIMATIC SUMMARY
2005

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

...ONE OF THE WARMEST YEARS ON RECORD IN SIOUX CITY IN 2005...

Temperatures averaged out to 51.3 degrees, or 3.0 degrees above normal, in Sioux City in 2005, for the 7th warmest year since records started in 1889. An indication of the persistence of the warmth was that a record 15 months in a row had at or above normal temperatures from September 2004 through November 2005. The old record was 11 months in a row from December 1920 through October 1921 with at least normal temperatures. Precipitation came out to near normal for 2005 with a total of 26.03 inches at the Sioux Gateway Airport. The following is a chronological account of the weather events of 2005 in the Siouxland...

January 5th...A record daily snowfall of 7.8 inches was recorded, disrupting and delaying travel. Up to 12 inches snowfall was reported east of Sioux City.

January 22nd...High northwesterly winds battered the Siouxland during the morning, with a gust of 66 mph at the airport at 131 AM, for the strongest recorded wind of 2005.

February 4-5th...Record daily highs were recorded on both days, with 66 degrees on the 4th and 61 degrees on the 5th.

March 10th...Another high wind event brought strong northwest winds gusting up to 60 mph at the airport at 211 PM. The winds caused some damage to roofs, trees, and power lines in the area.

April 20th...Heavy rains in the area produced street flooding in South Sioux City, Nebraska from 600 AM to 730 AM in the morning. At the Sioux City Airport there was 1.01 inches of rainfall with this system.

May 12th...A new record daily rainfall was set with 1.42 inches at the airport.

June 23rd...The daily high of 99 degrees was the warmest temperature of 2005.

June 28th...Thunderstorms produced hail up to nickel size east of Sioux City near Bronson, Lawton, and Moville around 1 AM.

July 20th...Thunderstorms produced 1.18 inches of rain within one hour between 5 and 6 AM at the airport. Also nickel size hail and 60 mph winds were reported at Hubbard, just southwest of Sioux City, at 525 AM.

July 22-24th...High temperatures in the mid 90s and daily low temperatures in the mid 70s with high humidity, produced very uncomfortable conditions for people without air-conditioning. Dewpoint temperatures, which indicate amount of moisture in the air, reached into the lower 80s at times. The heat index reached 119 degrees on the 22nd at 6 pm, and 116 degrees on the 23rd at 3 pm, for some of highest computed heat indices in recent weather records.

July 27th...A new record daily low of 50 degrees was established, beating the old record of 53 set just last year.

August 9th...Hail up to the size of quarters (up to 1 inch in diameter) was reported from 408 PM to 416 PM with thunderstorms in Sioux City.

September 20-21st...New record daily highs occurred on both dates, with 94 degrees on the 20th and 96 on the 21st.

September 25th...A new record daily rainfall record was set with 2.14 inches rain at the airport, which was also the heaviest precipitation event of 2005. Much of this rain, 1.36 inches, fell in one hour between 8 and 9 AM in the morning.

June through September...September 2005 tied 1998 for the 4th warmest September on record in Sioux City with an average temperature of 70.1 degrees, or 7.0 degrees above normal. This helped make the June through September 2005 period the 6th warmest such period on record with an average of 74.1 degrees. Some more trivia...the only other time besides this year that each of the months of June, July, August, and September all had an average monthly temperature above 70 degrees was in 1931 and 1939.

October 2-4th...Highs were in the lower 90s, with daily lows and dewpoint temperatures in the mid to upper 60s, making for a sultry last hurrah of summerlike weather. The daily average temperature of 80 degrees on the 3rd was the warmest daily average on record in the month of October. Thunderstorms with heavy rain signaled the end of the summer weather at Sioux City, with flooding of downtown streets from 630 to 800 PM on the 4th. The airport received 1.34 inches rainfall.

November 2nd...A new daily record high of 80 degrees beat the old record of 76 degrees set in both 1953 and 1965.

November 12th...Another record high occurred with 73 degrees, breaking the old record of 68 in 1954.

November 28-30th...The weather pattern changed dramatically on the 28th with a winter storm system bringing 1.20 inches precipitation, including 4.0 inches snowfall, and northwest winds gusting to 59 mph at the airport causing blowing snow. Another system brought 4.6 inches snowfall on the 30th to end the month on the wintry side.

December 1-9th...The new snow cover helped set the stage for an early season cold spell through the first 9 days of December, with daily highs of 20 degrees or less, and nighttime lows mostly near to below zero. There was also 4.5 inches new snowfall during this period, building up the snow on the ground to around 10 inches depth by the 8th. The coldest day was on the 6th with a high of only 5 degrees, and a record low of –16, which beat the old daily record of –12 set in 1976, and was also the low temperature of 2005. Temperatures recovered nicely after the 9th through the end of the month, melting off all the snow cover by the 22nd when the high for the day, and the month, was 53 degrees.

THE FOLLOWING TABLES GIVE A MONTH BY MONTH BREAKDOWN OF WEATHER IN 2005 AT THE SIOUX CITY AIRPORT...

TEMPERATURES

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

JANUARY        28.2 11.9     20.1    PLUS 1.5   57 13B
FEBRUARY       42.6 21.7     32.2    PLUS 7.1   66  2B
MARCH          52.5 25.2     38.9    PLUS 2.4   82 10
APRIL          66.6 41.4     54.0    PLUS 4.5   86 22
MAY            74.4 48.0     61.2        ZERO   89 27
JUNE           85.9 63.9     74.9    PLUS 4.4   99 52
JULY           89.2 65.6     77.4    PLUS 2.8   96 50
AUGUST         86.3 61.6     74.0    PLUS 1.9   98 51
SEPTEMBER      84.9 55.2     70.1    PLUS 7.0   97 29   4TH WARMEST
OCTOBER        66.8 38.9     52.9    PLUS 2.1   91 22
NOVEMBER       52.0 26.2     39.1    PLUS 4.3   80  6
DECEMBER       29.1 13.1     21.1   MINUS 1.2   53 16B

 2005          63.2 39.4     51.3    PLUS 3.0   99 16B  7TH WARMEST

NORMAL YEAR    59.5 37.0     48.3 

PRECIPITATION AND WINDS

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

JANUARY     .45   MINUS  .14      9.6     PLUS 3.3      NW 66 ON 22ND
FEBRUARY   1.12    PLUS  .50      3.7    MINUS 1.8       S 41 ON 5TH
MARCH       .80   MINUS 1.20      0.1    MINUS 5.7      NW 61 ON 10TH
APRIL      4.18    PLUS 1.43       0     MINUS 1.9      NE 49 ON 20TH
MAY        3.39   MINUS  .36       0                    NW 54 ON 27TH
JUNE       4.13    PLUS  .52       0                     W 43 ON 28TH
JULY       2.51   MINUS  .79       0                    NW 52 ON 21ST
AUGUST     1.45   MINUS 1.45       0                    NW 48 ON 3RD  
SEPTEMBER  2.84    PLUS  .42       0                     W 45 ON 22ND
OCTOBER    2.48    PLUS  .49       0     MINUS 0.8       W 44 ON 4TH
NOVEMBER   1.91    PLUS  .51     10.6     PLUS 5.8      NW 59 ON 28TH
DECEMBER    .77    PLUS  .11      6.6     PLUS 0.3      NW 41 ON 10TH

 2005     26.03    PLUS  .04     30.6    MINUS 0.8      NW 66 JAN 22ND

RICHARD S. RYRHOLM..CLIMATIC FOCAL POINT


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