Rules concerning the occurrence of a probability of precipitation (POP) forecast and its placement within public forecast bulletins are being standardized for all regions of Canada. Effective on the dates shown below, probabilities of precipitation will only be mentioned in forecasts when they are in the range from 30% to 70%, inclusive. Probabilities of 0% to 20% or from 80% to 100% will not be explicitly mentioned. In addition, in short-term forecasts, the statement "Probability of precipitation in percent" will no longer appear after the forecast for the next day. Rather, when necessary, the POP forecast will be included in the forecast for the period (e.g. today, tonight, Thursday). The example below illustrates the new rules.

The effective dates of these changes are as follows:
Newfoundland and Labrador, Nova Scotia, Prince Edward Island and New Brunswick: November 15, 2001.
Quebec: Already in effect
Ontario: November 8, 2001
Manitoba, Saskatchewan and Alberta: Already in effect
Northwest Territories and Nunavut: November 8, 2001
British Columbia and Yukon: Already in effect