• Return to Climate of 1999: January Overview
• Detailed Climate Perspectives . . .
  • Global Regional Analyses
    
  • U.S. National Analysis
    
  • U.S. Regional Analyses
    
  • U.S. Statewide Analyses
  • Extreme Events
    
• 1998 Monthly Reports

January 1999 Temperature

January 1999 Precipitation

January 1999 was unusually wet from the southern states to the Ohio Valley and Northeast, with 16 states having the wettest to tenth wettest January on record. An additional 18 states ranked within the wet third of the historical distribution (i.e., among the 35 wettest Januaries out of 105 years). January 1999 was dry from southwest Texas to southern California. Arizona ranked in the top ten driest category with the sixth driest January on record, and three other states ranked within the driest third category (top 35 driest Januaries on record).

larger image

Animated Map

Despite a cold outbreak that affected a large part of the country east of the Rockies early in the month, January 1999 averaged near normal to much warmer than normal for most of the U.S. The animated maps show the geographical pattern of temperature anomalies for the last 12 months. On these standardized temperature anomaly maps, red indicates areas with mean monthly temperatures much warmer than normal (top 10 percentile), tan indicates warmer than normal (70-90 percentile), light blue indicates colder than normal (10-30 percentile), and dark blue indicates much colder than normal (bottom 10 percentile).

The Palmer Z Index shows how monthly moisture conditions depart from normal (short-term drought and wetness). January 1999 was unusually wet from the southern states to the Ohio Valley and Northeast, much of which had been dry during the last half of 1998. January 1999 was dry from southwest Texas to southern California. The animated maps show the geographical pattern of the moisture anomalies for the last 12 months. On these Z Index maps, the red shading denotes dry conditions while the green shading indicates wet conditions.

Animated Map

Animated Map

The Palmer Drought Index Maps show long-term drought and wet conditions. The January 1999 wetness from the southern states to the Ohio Valley and Northeast helped reduce the impact of the long-term drought which had been building over the area during the last half of 1998. The animated maps show how the geographical pattern of the long-term moisture conditions has changed over the last 12 months. On these Palmer Drought Index maps, the red shading denotes drought conditions while the green shading indicates wet conditions.

December 1998 - January 1999 Temperature

larger image

Unusual warmth dominated most of the country during the two-month period, December 1998 to January 1999. Forty-five of the contiguous 48 states ranked within the top 35 warmest December-Januaries (i.e., the warm third of the historical distribution), and three states had the tenth warmest, or warmer, December-January in 1999.

December 1998 - January 1999 Precipitation

Nature played a regional balancing act for December-January 1998-99 precipitation. On the wet side, Montana ranked within the top ten wettest category with the tenth wettest December-January on record, followed by 26 other states in the top third wettest range (out of 104 December-January periods). On the dry side, Arizona led with the seventh driest December-January, followed by seven other states in the top third driest range (rank of 1 to 34 out of 104 years).

larger image

For further information, contact:

NCDC / Climate Research / Climate of 1999 / January / U.S.Statewide / Search / Help