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.
| Time Period term | Corresponding Time Period (local time) | Sub-time Period term | Corresponding Time Period (local time) |
| Morning | 6:00 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 Noon | 11:01 a.m. – 12:59 p.m. | ||
| Afternoon | 12 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 day | 3:00 p.m. – 11:59 p.m. | ||
| Evening | 6:00 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 Midnight | 11:01 p.m. – 12:59 a.m. | ||
| Overnight | 12 midnight – 5:59 a.m. | After midnight Late overnight | 12 midnight – 2:59 a.m. 3:00 a.m. – 5:59 a.m. |
- Types of Marine Forecasts
- Forecast Issue Times and Valid Periods
- Forecast Time Qualifiers in Relation to Clock Time
- What information is included in the Marine Forecast?
- Marine Forecasts – Sample Text Bulletins
- Marine Forecasts – Weatheroffice Website
- Forecast Updates – When and Why
- Major Weather Elements Included in the Marine Forecasts
- Interpreting the Wording of a Marine Forecast
- Marine Warnings and Watches Program
- Synoptic Warnings
- Localized Warnings & Watches
- Ice Warnings
- Date Modified: