Weather affects everyone, especially those of us involved in agriculture. The Southwest Missouri Center has been recording weather data continuously since 1960. The following is a collection of weather facts and figures for your information and amusement. The data contained in this report covers the period from January 1 through July 31, 2004, inclusive. Additional information for 2003 and averages from 1960 through 2003 are included for comparative purposes.

First, let's look at 2003 in review. With the exception of the violent storms that spawned several deadly tornadoes in early May, the year 2003 was a fairly mild, normal year. Considering the typical monthly ups and downs we see each year, we ended 2003 just a little warmer and a bit drier that average.

We began the year with January and February being cooler than normal, followed by a spring that was several degrees warmer than the 43-year average. For the remainder of the year, only June and September saw below normal. August was particularly warm, with a period during which the high temperatures climbed over 100°F for 9 out of 10 consecutive days. And despite a few brief cold spells, November and December were actually several degrees above normal.

The year ended with an overall mean temperature of 56.26°F or 0.75°F above normal, almost identical to the previous year (2002). There were no new monthly or yearly temperature records set in 2003.

The lowest temperature for 2003 was -1°F recorded on both Jan 18 and Jan 23. Temperatures fell below freezing (32°F or less) 98 days and reached 0°F or less three times. The highest temperature was attained for the year was 103°F on Aug 23. Temperatures reached 90°F or higher 47 days and climbed to 100°F 9 times.

The last severe frost (24°F or less) in the spring of 2003 occurred on April 10 with a reading of 24°F, and the last light frost (32°F or less) was just a day later on April 11 at 31°F. The first light frost of autumn 2003 was on November 7 at 26°F and a killing frost occurred on November 24 with a low of 19°F.

Precipitation for 2003 totaled 40.37", or 2.87" below normal. Five months (February, March, August, November and December) had above normal precipitation, but much of that was outside the normal growing season. Fortunately, the rains that did fall, particularly after August, were timely and of sufficient amounts that we had some of the best fall regrowth that we have seen in the past 5 years. There were no new monthly or yearly precipitation records set for 2003.

Looking at the first half of 2004 (data are from January 1 through July 31, inclusive), we have seen a general turnaround in the drought that we have been experiencing for the past 5 years. With the exception of February which received only 0.41" and June, typically our wettest month of the year, which was about a half inch below normal, every other month received at least an inch more precipitation than average. In fact, July set a new record for the month with 8.79" or rain, 5.53" above normal! As of July 31, we stand at 11.68" above normal with a total 36.15" (Jan 1 thru Jul 31). There has only been one notable dry spell so far in 2004, a 27-day stretch in February during which we received only 0.15" of precipitation.

We have seen wide swings in monthly average temperatures. January, March and May have all been several degrees warmer than normal, while July has been significantly below average. The last severe frost occurred all the way back on February 26 with a reading of 23°F, and our last light frost was on April 14 at 32°F. The lowest temperature so far in 2004 was 2°F on January 2, and the high temperature of 95°F was seen on July 14 and 15. As of July 31, we have only had 10 days when the temperature reached or exceeded 90°F; that is about half of what we usually see by that date.

We continue to plot our long term trends in precipitation and temperature (see graphs below). We are still seeing a general rise in the amount of precipitation, amounting to an average increase of 0.11" per year since 1960. It is interesting to note, however, that this trend has been getting smaller and smaller over the past few years. In 1993, the trend or regression line had a slope of +0.39" per year meaning, that between 1960 and 1993, the amount of precipitation was increasing an average of 0.39" each year. With below average precipitation in eight out of the past nine years, the regression line has flattened out considerably to where the average annual increase is now only 0.11", less than a third of what we would have predicted back in 1993.

If one looks at the overall actual precipitation line in the graph below, we start to see more of a curve rather than a straight-line response. In the 1960's, the climate was much drier than today, averaging only 38.61" per year for the decade. Precipitation in the 70's and 80's was more than 6" higher per year than in the 60's. In the first half of the 90's, three years (1990, 1992 and 1993) saw rainfall totals of well over 50" per year. The second half of the 90's, however, has seen only one year (1998) with above normal precipitation. If the rest of 2004 is anything like the first 7 months, however, the expected above average yearly total could go a long way in reversing the downward trend we’ve seen during the last decade.

Unlike precipitation which has shown wide swings up and down, temperatures have remained relatively constant since 1961. The slope of the regression (trend) line actually shows a slight decrease of 0.004°F annually, hardly enough to notice. There does not appear to be any long term pattern or cycle, although there does appear to be small cycles of 4 to 6 years, giving the mean temperature line somewhat of a saw tooth look. These small humps can be seen from 1976 to 1979, 1979 to 1983, 1985 to 1989, 1989 to 1993, 1993 to 1997, and most recently 1997 to 2000. Right now it appears that we might be in the middle of yet another "mini-cycle".