Weather forecasts

Below is some general information regarding the weather forecasts that the Cirrus Forecast service creates.

Update frequency

Depending on which plan you subscribe to, the weather forecast gets updated at different times and frequencies. Below you will find a breakdown for each plan.

Daily plans

Daily plans include weather seven (7) days a week.

Plan Updates per day Hours updated
Stratus 5 12am, 6am, 12pm, 5pm, 9pm
Cumulus 8 12am, 3am, 6am, 9am, 12pm, 3pm, 6pm, 9pm
Nimbus 12 12am, 2am, 4am, 6am, 8am, 10am, 12pm, 2pm, 4pm, 6pm, 8pm, 10pm
Cirrus 24 Every hour

Weekend plans

Weekend plans run from Friday at 12:00 PM through Monday at 11:00 AM (depending on your plan) giving three days of forecasts. We provide this range in order to accommodate different weekend hours for our customers.

Please see the above table under Daily for which hours during the weekend your specific plan will be updated. The table below shows when each plan will start and end for the weekend.

Plan First forecast for the weekend Last forecast created for the weekend
Stratus Friday at 12pm Monday at 6am
Cumulus Friday at 12pm Monday at 9am
Nimbus Friday at 12pm Monday at 10am
Cirrus Friday at 12pm Monday at 11am

Time of day

Period Time
Morning 6:00:00 AM – 11:59:59 AM
Afternoon 12:00:00 PM – 4:59:59 PM
Evening 5:00:00 PM – 8:59:59 PM
Night 9:00:00 PM – 5:59:00 AM

New forecast availability

Forecasts for the following hour are created by default 15 minutes before that hour (0:45) so it will be available before the top of the hour.

When the forecast is generated can be overridden by setting the "Generation time" in the admin web portal. The range is 0:45 through 0:15 which equates to 15 minutes before the top of the hour through 15 minutes after the top of the hour.


The following examples assume the subscribed location is on the Cirrus plan receiving updates on an hourly basis.

  • If the generation time equals "0:45", the weather forecast file for 1:00 PM will be created around 12:45 PM (before the top of the hour).
  • If the generation time equals "0:50", the weather forecast file for 1:00 PM will be created around 12:50 PM (before the top of the hour).
  • If the generation time equals "0:00", the weather forecast file for 1:00 PM will be created around 1:00 PM (at the top of the hour).
  • If the generation time equals "0:10", the weather forecast file for 1:00 PM will be created around 1:10 PM (after the top of the hour).

{warning} There must be at least a six (6) minute window from the generation time to the time the file needs to be downloaded. For example, if the forecast will be broadcasted at 1:12 PM, the generation time needs to be set to a minimum of 0:06. A generation time of 0:07, 0:08, etc. would not give enough time for the forecast to be generated and downloaded by the Cirrus Forecast Downloader.

Weather Alerts

Weather alerts are available on the Cirrus plan. This is to ensure alerts are always up-to-date and expired alerts are not included.

Alerts in the United States are from the National Weather Service. If you are in another country, please contact us and we can check to see if alerts are available in your area.

A few general notes:

  • All active and future alerts are announced at the beginning of the forecast
  • Alerts are sorted by severity - warnings, watches, and then advisories
  • If there are many alerts, some may be removed starting with advisories to make sure the forecast fits within 30 seconds
  • Maritime related alerts are not included

Climate adjustments

A climate adjustment allows you to adjust the words used in your weather forecast for the winter and summer months depending on if your climate is colder or warmer than average during those months. The climate adjustment is done by setting a temperature adjustment between -30 and +30 in increments of 10. An adjustment can be made for the winter and the summer independently.

{info} For climate adjustments in the Northern Hemisphere, winter is considered to be November through April and summer is considered to be May through October. In the Southern Hemisphere, winter is considered to be May through October and summer November through April.

The average temperatures we use are between 20-35°F in the winter and between 70-85°F in the summer. Extremes are considered below 0°F and above 100°F.

The table below is a loose guide to help you determine if you need to make a climate adjustment. Please note that temperatures are in Fahrenheit.

Adjustment to make Winter average Summer average Low extreme High extreme
-30 -10 to 5 40 to 55 Below -30 70 and above
-20 0 to 15 50 to 65 Below -20 80 and above
-10 10 to 25 60 to 75 Below -10 90 and above
0 (default) 20 to 35 70 to 85 Below 0 100 and above
+10 30 to 45 80 to 95 Below 10 110 and above
+20 40 to 55 90 to 105 Below 20 120 and above
+30 50 to 65 100 to 115 Below 30 130 and above

Using SSML syntax

SSML stands for Speech Synthesis Markup Language. You can find more information about it here.

If you are having issues with a voice pronouncing a word incorrectly whether it be within your station name, slogan or sponsor, we might be able to use some specific SSML syntax. Please contact us through Support and we can help you with the syntax. Just let us know the word or phrase you are having an issue with and which voice.

{warning} In order to support SSML, we had to make parenthesis reserved characters. This means that you cannot use ( or ) in any text unless you have worked with us and we told you to. If you do, you will run into issues with your weather forecasts generating.