Global Highlights:

• Based on preliminary data for September 2004, global average combined land and sea surface temperature was fourth warmest on record
• September temperatures were above average throughout the northern Great Plains of the U.S., the eastern half of Canada and Japan, with below average temperatures in Alaska, Mongolia and western Australia
• Precipitation during September was above average across the eastern U.S., Alaska and Southeast Asia, with drier than average conditions in the Lower Mississippi Valley of the U.S., Brazil and eastern Europe
• Above normal SSTs across the central and equatorial Pacific basin suggest a weak El Niño is developing

Contents of this Section:

• Introduction
• Global Temperatures
• Global Precipitation
• ENSO SST Analysis
• Troposphere
• Stratosphere

The data presented in this report are preliminary. Ranks and anomalies may change as more complete data are received and processed. The most current data may be accessed via the Global Surface Temperature Anomalies page.

Introduction

Temperature Rankings and Graphics

Precipitation

The maps below represent anomaly values based on the GHCN data set of land surface stations using a base period of 1961-1990. The map to the left is precipitation anomalies measured in millimeters, the map to the right is the percentage of average (1961-1990) precipitation. During September 2004, much above average precipitation fell across the southeastern U.S., southern portions of Alaska, the Caribbean, southeastern Asia, Sri Lanka and Scandinavia. Below average precipitation was observed in the southern Great Plains of the U.S., the Philippines, western parts of Canada, eastern Europe and Brazil.

ENSO SST Analysis

Click here for animated loop

• A consensus of indices suggests above normal SSTs in the central and equatorial Pacific basins which suggests ENSO was in a weak warm phase (El Niño) during September 2004 (as shown in the adjacent animation of weekly sea surface temperature anomalies). A comprehensive summary of September 2004 ENSO conditions can be found on the ENSO monitoring page. For the latest advisory on ENSO conditions go to NOAA's Climate Prediction Center (CPC) and the CPC ENSO Diagnostic Discussion