Frequently Asked Questions

How many weather stations do you support?

Weather Source maintains archives for nearly 50,000 stations worldwide, of these approximately 26,000 are currently active stations. In the US about 15,000 are currently active and of these approximately 3000 provide both hourly and daily data, while the remainder report daily weather summaries.

What weather data do you offer? 

We archive a broad selection of weather parameters, in addition, we create customized parameters derived from common variables. Please note that not all weather stations will have all the below weather variables. In general, stations that report hourly observations will have all the below listed variables. Stations that report only daily summaries generally only provide temperature and precipitation information.

For each of the weather variables listed below we can provide information on hourly increments and as daily totals, maximums, minimums and averages as appropriate.

If your business requires a unique weather type not listed below, Weather Source will be happy to create it for you. One example of custom weather information is our Virtual Hourly Rainfall which provides estimated hourly rainfall for stations that don't report it. Virtual Hourly Rainfall is derived from accumulated rainfall reports (e.g. 6-hourly and 12-hourly rainfall) and other weather variables via Weather Source's RainMaker Methodology.

Relative Humidity
Wind speed & direction
Gust wind speed
Peak wind speed & direction
Cloud cover (Can be used to approximate % sunshine)
Sea Level Pressure
Station Pressure
Rain indicator
Freezing Rain indicator
Sleet indicator
Snow indicator
Fog indicator
Severe weather indicator (lightning, thunder, hail)
Heating degree days (HDD)
Cooling degree days (CDD)
Growing degree days (GDD)
Heat index
Wind chill
Wet bulb temperature
Weather Source Exclusive
Virtual Rainfall
Feels-like Temperature (Appropriate blending of Wind Chill and Heat Index)
Weather Source Business Weather Indices (Daily indices relevant to business)

Business Day Fair Weather Index
Dining & Entertainment Fair Weather Index
Sun angle
Begin time of civil twilight (dawn)
Time of sunrise
Time of sunset
End time of civil twilight (dusk)

Do you have the "official" values as published by NCDC (National Climatic Data Center)?

Yes, we continually ingest the official values as published by NCDC as it becomes available. In addition if you need "certified" paper copies of weather information to support a legal case we can help you with that. To do this we recommend that you use the Weather Source database to find the most useful information for your case. This is an important step, since in many cases weather information from a station assumed to be a good choice may actually not have what you need to support your case. By checking the Weather Source database first, you can be confident you are ordering the appropriate certified data. After verifying you have found the best weather information to support your case, Weather Source can have the certified paper copies mailed to you. The cost for this service varies with the amount of certified data you need. For most cases the fee is $200.