SWMM - Climate File

SWMM can use an external Climate File that contains daily air temperature, evaporation, and wind speed data. The program currently recognizes the following formats:

• Global Historical Climatology Network - Daily Files (GHCN-D) (TEXT output format) available on NOAA's National Climate Data Center (NCDC) Climate Data Online service at www.ncdc.noaa.gov/cdo-web
• Older DS3200 or DS3210 NCDC files
• Canadian Climate Archives - available from Environment Canada at www.climate.weather.gc.ca
• User Defined - A user-prepared Climate File where each line contains a recording station name, year, month, day, maximum temperature, minimum temperature, and optionally temperature rate. evaporation and wind speed. If no data is available for any of these items on a given date, an asterisk must be entered as its value. Example:
  

  STA01 2004 6 12 00 00 0.12
  STA01 2004 6 12 01 00 0.04
  STA01 2004 6 22 16 00 0.07
  STA01 2004 6 22 * 00 0.07

When a Climate File has days with missing values, SWMM will use the most recent previous day's value as a recorded value.

Note: For a user-prepared Climate File, the data must be in the same units as the project being analyzed. For US units, temperature is in degrees F, evaporation is in inches/day, and wind speed is in miles/hour. For metric units, temperature is in degrees C, evaporation is in mm/day, and wind speed is in km/hour.