National Climatic Data Center, 15 June 2001

Contents of This Report:

• Statewide Temperature Ranks
• Statewide Precipitation Ranks
• Regional Temperature Highlights
• Regional Precipitation Highlights
• Regional Temperature and Precipitation Time Series
• Agricultural Precipitation
• Precipitation and Temperature Ranks, Extremes and Normals
• Water-year River Basin Statistics
• Spring (March-May)

Statewide Temperature Ranks

Larger Map

Nevada had its record warmest May in the 1895 to present record. The five other states that ranked in the top ten warmest Mays were California - second warmest Arizona - fifth warmest Utah - sixth warmest New Mexico - seventh warmest Maine - ninth warmest Twenty-five other states fell into the warm third of the historical distribution. The May 2001 temperature anomaly animation map reflects positive anomalies for much of the country. No state in the contiguous United States fell in the bottom third of the historical distribution.

Statewide Precipitation Ranks

West Virginia had its sixth wettest May in 107 years while Michigan and Iowa experienced their seventh wettest. Eleven other states fell into the wet third portion of the historical distribution. Rainfall reached record proportions in Charleston, WV (8.76 inches), and totaled 9.72 inches in Muskogee, OK, 4.76 inches of which fell in 24 hours on May 29-30. In contrast, May was an extremely dry month for many states. Montana and Nevada were fifth driest and California was ninth driest. Fourteen additional states were in the lower third of the historical distribution. Rainfall was the lowest on record in locations such as Tampa, FL (a trace), Ft. Myers, FL (0.20 inch), and Kalispell, MT (0.23 inch).

Larger Map

Regional Temperature Highlights

Based upon preliminary data, May 2001 was the record warmest such month in the 1895 to present record for the West region. Seven of the last ten Mays were above the long-term mean. On the 30th in California, May-record highs were broken in Cuyama when temperatures reached 105° F (40.6° C) and in downtown San Francisco where 101° F (38.3° C) was recorded. San Francisco's previous May record, 97° F (36.1° C), had stood since 1887.

larger image

larger image

It was the sixth warmest May in the 1895 to present record for the Southwest region. Fourteen of the last eighteen Mays were near to or above above the long-term mean.

Regional Precipitation Highlights

May 2001 was the fifth driest such month in the 1895 to present record for the West region. This continues the three year trend of May precipitation averaging near to or below the long-term mean. In May 1998, the West region experienced near-record precipitation.

larger image

larger image

It was the eighth wettest May for the East North Central region in 107 years. Near to or above normal precipitation has been recorded in six of the last seven Mays.

Regional Temperature and Precipitation Time Series

Additional information about current climate anomalies can be found at the respective Web Pages of the Southern Regional Climate Center, Western Regional Climate Center, Midwest Regional Climate Center, Southeast Regional Climate Center, High Plains Regional Climate Center, and the Northeast Regional Climate Center.

Historical precipitation and temperature ranking maps are also available on the Internet courtesy of the Climate Prediction Center.

Agricultural Precipitation

Precipitation averaged across the Primary Corn and Soybean agricultural belt was near normal for March through May 2001. Six of the last seven such periods have been near to or above normal. The growing season for the Primary Corn and Soybean Belt runs from March through September. For further agricultural information visit the Weekly Weather and Crop Bulletin.

larger image

Data Tables

Table 2 shows historical extremes for May, the 1961-1990 normal, and the May 2001 value for each of the 9 regions and the contiguous U.S. for precipitation and temperature.

Table 3 shows statistics for selected river basins: Precipitation rankings are for October 2000-May 2001, where 1 = driest, and 106 = wettest, based on the period 1895 to 2001. Also shown is the areal percent of the basin experiencing severe or extreme long-term (Palmer) drought, and areal percent of the basin experiencing severe or extreme long-term (Palmer) wet conditions, as of May 2001. The river basin regions are defined by the U.S. Water Resources Council.

It should be emphasized that all of the temperature and precipitation ranks and values in Tables 1 through 3 are based on preliminary data. The ranks will change when the final data are processed. National ranks and values are based on a combination of USHCN and divisional data.

Spring (March-May) Statewide Temperature Ranks

Larger Map

Nevada had its third warmest March-May in the 1895 to present record. The three other states that had springs that ranked in the top ten warmest were Utah - seventh warmest New Mexico - ninth warmest Arizona - tenth warmest Twenty-two other states fell into the warm third portion of the historical distribution. Only Alabama and Georgia ranked in the cool third of the historical distribution.

Spring (March-May) Statewide Precipitation Ranks

Minnesota had its fourth wettest spring in 107 years while Michigan experienced its seventh wettest. Ten other states fell into the wet third portion of the historical distribution. In contrast, spring 2001 was the second driest spring on record for Maine. Twelve additional states ranked in the dry third portion the historical distribution.

Larger Map

Spring (March-May) Regional Temperature Highlights

Based upon preliminary data, spring 2001 was the seventh warmest spring in the 1895 to present record for the West region. Fourteen of the last eighteen springs were above the long-term mean.

larger image

larger image

It was the eighth warmest March-May in the 1895 to present record for the Southwest region. Fifteen of the last eighteen springs were near to or above above the long-term mean.

Spring (March-May) Regional Precipitation Highlights

March-May 2001 was the twenty-seventh driest spring in the 1895 to present record for the Northeast region. This contrasts with above normal wetness nine of the last thirteen springs. The Central region also experienced its twenty-seventh driest spring.

larger image

larger image

It was the sixth wettest spring for the East North Central region in 107 years. In fact, for the year long period ending in May, the East North Central region ranked as sixth wettest as well.

References

Thomas R. Karl and Albert J. Koscielny, 1982: "Drought in the United States: 1895-1981." Journal of Climatology, vol. 2, pp. 313-329.

Thomas R. Karl and Walter James Koss, 1984: "Regional and National Monthly, Seasonal, and Annual Temperature Weighted by Area, 1895-1983." Historical Climatology Series 4-3, National Climatic Data Center, Asheville, NC, 38 pp.

Questions?

NCDC / Climate Monitoring / Climate of 2001 / May / Search / Help