WEATHER INFORMATION

The 2001 crop year for Dawson County was another very dry year with the bulk of the dryland cotton acres being failed out. The years total rain fall was only 10.19 inches, with only 5.81 inches from May thru October. Heat units for the growing season were above the 68 year long term accumulation by 278 heat units (May - October).

Irrigated crops were average or above for most producers, some experienced lower yields due to limited irrigation water.

The harvest weather was open and clear for the most part.

As all ways we were glad 2001 crop year was over, and hopefully looking for better days during 2002.

Climate of Lamesa, Texas and Dawson County

Lamesa is located on the high, level South Plains region of Northwest Texas, at an elevation of 2965 feet. It is near the center of Dawson County, and about eleven miles west of the Caprock Escarpment. Sulfur Springs Draw is oriented northwest to southeast across Dawson County, and runs through Lamesa. Fertile loam to sandy loam soils cover most of the Plains area of the county with some sandy lands in the western part. Lamesa is the center of a rich crop-livestock area.

The climate of Lamesa is semi-arid. It is characterized by extreme variability both in rainfall amounts and temperatures. Sunshine is abundant, with the infrequent cloudy weather occurring mostly during the winter and early spring months.

The average rainfall is 17.61 inches, but this value may be misleading because of the large differences from one year to the next. Extremely dry years were 1934, 1946, 1951, 1952, 1953, and 1965 and 1998 (10.12), with less than 10 inches. Only 7.06 inches fell in 1956. The wettest year on record was 1941 with 39.07 inches (233% of normal). More than 27 inches fell in 1932, 1935, and 1986. Seventy-five percent of the average annual rainfall occurs during the warmer half of the year, May through October. Most of this warm season rainfall is the result of thunderstorm activity, which helps to account for the extreme variability in amounts from year to year, and from one location to another.

Snow falls occasionally during the winter months, but is generally light, and remains on the ground only a short time. Infrequently, deep low pressure centers will develop over the South Plains during late January or February that will produce heavy snows in the region, but these excessive amounts are rare.

Temperatures, like rainfall, vary over a wide range. Winters are characterized by frequent cold periods followed by rapid warming. This produces frequent and pronounced temperature changes. Summers are hot and usually dry except for small thundershowers. Low humidity and adequate wind circulation, resulting in rapid evaporation help to moderate the effect of the heat. Evaporative coolers are quite efficient in the area.

The prevailing wind is from the south from about May through October, and from the southwest, November through April. The strongest winds occur during the severe thunderstorms of late spring and early summer, but these are gusts or squalls of short duration. The strongest continuous winds occur during March and April as a result of intense low pressure centers that originate on the High Plains region just to the east of the Rocky Mountains. These winds often produce severe dust storms in the region during drought years.

Humidity is rather low, with the highest values occurring during the early morning hours, and the lowest during the afternoons. Early morning values may be expected to average about 75 percent, while afternoon values will average between 40 and 45 percent. As would be expected, evaporation is high in this semi-arid region. Average annual lake evaporation is estimated at 72 inches per year.

Hail may accompany thunderstorms anytime they occur; however, the most damaging hailstorms are usually associated with the severe thunderstorms of the late spring or early summer.

The growing season is short when compared to Central or South Texas, but sufficiently long for cotton. The average freeze free period [the number of days between the last occurrence of 32 degrees F in the spring (April 2) and the first occurrence of 32 degrees in the fall (Nov. 4)] is approximately 216 days.

Lamesa’s Freeze Dates for the Past 53 Years

                          Last Freeze                         First Freeze                Length of

Year                  in Spring                         in the Fall              Growing Season

1949                    April 5                               October 31                             209 days

1950                    April 6                               November 4                          212 days

1951                    April 14                             November 2                          202 days

1952                    April 11                             November 10                        213 days

1953                    Missing                             November 9 

1954                    April 2                               October 31                             212 days

1955                    March 29                           October 25                             210 days

1956                    April 11                             November 5                          208 days

1957                    April 14                             October 27                             196 days

1958                    March 20                           November 1                          226 days

1959                    April 15                             October 28                             196 days

1960                    April 4                               October 31                             210 days

1961                    April 17                             November 3                          200 days

1962                    April 2                               Missing 

1963                    March 20                           November 23                        248 days

1964                    April 10                             November 20                        224 days

1965                    March 27                           November 27                        245 days

1966                    March 25                           November 2                          222 days

1967                    March 16                           November 4                          243 days

1968                    April 4                               November 11                        221 days

1969                    March 27                           October 31                             200 days

1970                    April 3                               October 10                             190 days

1971                    April 7                               November 18                        225 days

1972                    March 31                           October 31                             214 days

1973                    April 11                             November 22                        225 days

1974                    April 5                               November 25                        234 days

1975                    April 4                               November 13                        223 days

1976                    March 31                           October 9                              192 days

1977                    April 5                               November 2                          211 days

1978                    April 11                             November 7                          210 days

1979                    April 4                               November 1                          211 days

1980                    April 14                             October 29                             198 days

1981                    March 23                           November 10                        233 days

1982                    March 8                             November 4                          242 days

1983                    April 8                               November 28                        234 days

1984                    April 5                               November 27                        235 days

1985                    March 5                             November 20                        258 days

1986                    March 22                           November 11                        222 days

1987                    April 3                               November 10                        221 days

1988                    March 20                           November 16                        241 days

1989                    April 11                             October 19                             192 days

1990                    March 26                           October 22                             211 days

1991                    April 1                               October 30                             213 days

1992                    April 4                               October 8                              188 days

1993                    April 9                               October 30                             204 days

1994                    April 12                             November 16                        218 days

1995                    April 24                             November 3                          192 days

1996                    April 6                               October 22                             199 days

1997                    April 15                             October 27                             197 days

1998                    March 21                           November 11                        236 days

1999                    April 17                             November 3                          201 days

2000                    April 5                               November 7                          207 days

2001                    March 28                           October 16                             202 days

Average             April 2                               November 4                          216 days

Cotton Crop Heat Unit Calendar for Dawson County - 2001

Comparison of the Long Term Average Heat Unit Accumulation

with the

2001 Monthly Heat Unit (DD60) Accumulations at Lamesa, Texas

^A/ 68 Year Average                            ^B/ 14 Year Average         Prepared by John Farris, CEA-AG

Cotton Heat Unit Requirement

2001 Weather Data*

Average Temperature by Months 1997 through 2001

      2001 Monthly Average Temperature - 60.75                           *From Lamesa Reporting Station

Peanut Crop Heat Unit Calendar for Dawson County - 2001

Comparison for the Long Term Average Heat Unit Accumulation

with the 2001 Monthly Heat Unit Accumulations at Lamesa, Texas

^A/ 9 Year Average (DD-55, Max 95°F)                                                 Prepared by John Farris, CEA-AG

Irrigation Schedule for Peanuts Dawson County

NOTE:

FROM FRUIT INITIATION UNTIL MAXIMUM SOIL TEMPERATURE IN THE POD ZONE

DROPS TO 80 F - IRRIGATE 1.5 TO 2.5"/WEEK

AFTER MAXIMUM SOIL TEMPERATURE DROPS BELOW 80 F - REDUCE IRRIGATION

TO INCREASE MATURATION.

PLANTING

EMERGENCE (7 TO 21 DAYS)

BLOOM (45 DAYS AFTER EMERGENCE)

PEGS (PENETRATE SOIL 10 TO 14 DAYS AFTER BLOOM)

PODS (START 3 TO 4 DAYS AFTER PEGS HIT THE GROUND)

RUNNERS 155 DAYS AFTER EMERGENCE

VIRGINIA 145 DAYS

SPANISH 140 DAYS

VALENCIA 140 DAYS

Dawson County 70-Year Rainfall Record* 1932-2001

*From: Lamesa Reporting Station.