The weather in Fort Weyr varies according to altitude - a typical trait of the Great Western Mountain Range.

Springtime arrives to Fort's low valleys in month 4 and to the high countryside in month 6. The summer season is short, but summer days are long. Month 7 is the warmest month with a mean daily maximum temperature of 22.5ºC (72.5ºF). The autumn months of 9 and 10 usher in bright colors amid clear skies and cooler temperatures. The winter season is long and variable with cold and stormy periods that quickly switch to mild chinook winds. Month 1, the coldest month, has a mean maximum temperature of -11.1ºC (12º F).

In mountain terrain, a number of factors influence climate and weather patterns, and create a variety of micro-climates. These factors include elevation, latitude, prevailing winds, shading from mountains, alignment of valleys, and winds from the glaciers.

Altitude greatly influences the local climate: the higher the elevation, the colder the temperature. Generally, every increment of 300 feet signifies a loss in temperature of 1.7ºC (3.06ºF).

The winds from the southwest also have a major impact on local weather. The winds from the Western Sea bring warm air and moisture to the mountains despite its location. The winds have usually lost most of their moisture by the time they reach the eastern slopes.

Fort's Seasons

Fort Weyr has four primary seasonal changes: Winter, Spring, Summer and Autumn. The following is a breakdown in what month each of these seasons encroaches on the Weyr proper.

Remember: A year on Pern is called a Turn. Each Turn consists of thirteen months of twenty-eight days. These months contain the equivalent of weeks, referred to as sevendays, each containing a rest day. The seventh day of the week, or days 7, 14, 21, and 28 of each month, are designated as rest days. In addition, each Turn contains two additional holidays: Turn's End and Turn's Beginning, together known as Turnover. A leap day is included every six Turns. Months and days are not named, but are indicated by number (month 1, 2, up to 13 and day 1, 2, up to 28).

Month Season Average High Average Low
Month 1 Winter 0ºC / 32ºF -30ºC / -22ºF
Month 2 Winter 7ºC / 44.6ºF -15ºC / 5ºF
Month 3 Winter - Spring 10ºC / 50ºF -10ºC / 14ºF
Month 4 Spring 14ºC / 57.2ºF -8ºC / 17.6ºF
Month 5 Spring - Summer 17ºC / 62.6ºF 5ºC / 41ºF
Month 6 Summer 21ºC / 69.8ºF 10 ºC / 50ºF
Month 7 Summer 27ºC / 80.6ºF 14ºC / 57.2ºF
Month 8 Summer - Autumn 25ºC / 77ºF 16ºC / 60.8ºF
Month 9 Autumn 23ºC / 73.4ºF 14ºC / 57.2ºF
Month 10 Autumn - Winter 12ºC / 53.6ºF 0ºC / 32ºF
Month 11 Winter 12ºC / 53.6ºF 0ºC / 32ºF
Month 12 Winter 5ºC / 41ºF -10ºC / 14ºF
Month 13 Winter 0ºC / 32ºF -20ºC / -4ºF