Guide to Environment Canada Marine Weather Forecasts

Forecast Time Qualifiers in Relation to Clock Time

For simplicity, the marine forecast will make use of a limited number of time-qualified phrases such as “diminishing early this afternoon” or “ending tonight” to convey information about when significant changes to the marine weather are expected to occur.

These timing phrases are defined based on (local) clock time. For reference, forecast timing phrases and their associated defined clock times are stated in Table 2 below.

Table 2.  Time and Sub-time Period Definitions 
Time Period termCorresponding Time Period (local time)Sub-time Period termCorresponding Time Period (local time) 
Morning6:00 a.m. – 11:59 a.m.

Early morning

Late morning

6:00 a.m. – 08:59 a.m.

9:00 a.m. – 11:59 a.m.

Near Noon11:01 a.m. – 12:59 p.m.  
Afternoon12 noon – 5:59 p.m.

Early afternoon

Late afternoon

12 noon – 2:59 p.m.

3:00 p.m. – 5:59 p.m.

Late in the day3:00 p.m. – 11:59 p.m.  
Evening6:00 p.m. – 11:59 p.m.

Early evening

Late evening

6:00 p.m. – 8:59 p.m.

9:00 p.m. – 11:59 p.m.

Near Midnight11:01 p.m. – 12:59 a.m.  
Overnight12 midnight – 5:59 a.m.

After midnight

Late overnight

12 midnight – 2:59 a.m.

3:00 a.m. – 5:59 a.m.