Moonshae Climate

Written by Hellfell

The climate of the Moonshae Islands provides much of the atmosphere of this game setting, so it deserves to be given careful consideration. A DM may simply use the following procedures as a guide, making up for himself the weather on each given day of the adventure. This can become an important story consideration; many an adventure should reach its thrilling climax in the midst of a raging thunderstorm or crashing gale.
Alternatively, procedures exist that will enable the DM to determine, randomly and relatively quickly, the weather at any given time. For those players who wish to use the very detailed system from the Wilderness Survival Guide to determine weather in the Moonshaes, consider the islands to be a Subarctic Clime.
The climate of the Moonshaes can best be described as severe, especially during the long winter months. Each month is described separately in the following text, with probabilities for various types of weather listed. Whenever the weather can be an important part of an adventure, check on a daily basis.
The Average Daily Temperature for a month can fluctuate wildly. To get a range for game purposes, roll 2d6. If the result is 7, the temperature falls right into the range for a given day. Higher numbers mean higher than average temperatures; lower numbers mean the opposite. Thus, a 12 would mean abnormally warm temperatures on a given day, while a 2 would mean unusually cold weather.
If you need an exact temperature, take the difference between the number rolled and 7 and multiply it by 5 to determine the variance from the normal temperature. For example, if the roll is an 11, the difference between 11 and 7 is +4, multiplied by 5 to get +20. Therefore this day is 20 degrees warmer than is normal for this month. In nearly all cases, a general approximation will do, but if you need an exact number for some reason, you can use this fast method.
All temperatures in the Forgotten Realms are given on the Fahrenheit scale, so water freezes at 32 degrees. For further realism, add 1 to the 2d6 roll if the previous day’s temperature was warmer than normal; subtract 1 if it was colder than normal.
The Fog percentage listed for each month is the chance that at least part of the day is spent beneath the heavy mists that are so common on the isles. If fog is indicated, it develops between 1 and 6 AM (roll 1d6) and persists for 2d12 hours.
To determine cloudiness, which is different from fog, a type of die is listed for each month. Roll the appropriate die. On a result of 1-2, the day is clear. On a 3-4, it is a partly cloudy mixture of sunny skies and cumulous clouds. On a roll of 5 or more, it is overcast.
Precipitation occurs only on overcast days. The chart for each month lists a percentage chance of precipitation occurring, and often a guideline as to what type of precipitation falls. Determine the amount of precipitation as indicated for each type.

Weather Tables

Hammer (January)
Average Daily Temperature
High: 23
Low: 0
Fog: 75%
Cloudiness: 1d20
Precipitation: 60%

D20 Roll Result

1 Rain (.1-.4 inches)
2-19 Snow (1d6 inches)
20 Snow (2d10 inches)

Alturisk (February)
Average Daily Temperature
High: 28
Low: 6
Fog: 60%
Cloudiness: 1d12
Precipitation: 50%

D20 Roll Result

1-2 Rain (.1-.4 inches)
3-19 Snow (1d6 inches)

Ches (March)
Average Daily Temperature
High: 33
Low: 14
Fog: 80%
Cloudiness: 1d20
Precipitation: 75%
D20 Roll Result
1-7 Rain (.1-.8 inches)
8-10 Sleet
11-20 Snow (1d6 inches)

Tarsakh (April)
Average Daily Temperature
High: 40
Low: 28
Fog: 70%
Cloudiness: 1d10
Precipitation: 75%

D20 Roll Result

1-16 Rain (.1-.8 inches)
17-18 Rain (1d4 inches)
19-20 Snow (1d10 inches)

Mirtul (May)
Average Daily Temperature
High: 60
Low: 42
Fog: 60%
Cloudiness: 1d8
Precipitation: 60%

D6 Roll Result

1-5 Rain (.1-.6 inches)
6 Rain (1d4 inches)

Kythorn (June)
Average Daily Temperature
High: 70
Low: 50
Fog: 40%
Cloudiness: 1d6
Precipitation: 50%

D6 Roll Result

1-5 Rain (.1-.4 inches)
6 Rain (1d4 inches)

Flammerule (July)
Average Daily Temperature
High: 76
Low: 53
Fog: 40%
Cloudiness: 1d6
Precipitation: 40%
D6 Roll Result
1-5 Rain (.1-.4 inches)
6 Rain (1d4 inches)

Eliasias (August)
Average Daily Temperature
High: 75
Low: 50
Fog: 50%
Cloudiness: 1d6
Precipitation: 60%
D6 Roll Result
1-4 Rain (.1-.8 inches)
5-6 Rain (1d4 inches)

Eleint (September)
Average Daily Temperature
High: 69
Low: 45
Fog: 65%
Cloudiness: 1d8
Precipitation: 60%

D8 Roll Result

1-6 Rain (.1-.8 inches)
7 Rain (1d4 inches)
8 Sleet

Marpenoth (October)
Average Daily Temperature
High: 57
Low: 36
Fog: 75%
Cloudiness: 1d10
Precipitation: 50%

D6 Roll Result

1-3 Rain (.1-1 inch)
4 Sleet
5-6 Snow (1d4 inches)

Uktar (November)
Average Daily Temperature
High: 48
Low: 30
Fog: 85%
Cloudiness: 1d12
Precipitation: 60%

D8 Roll Result

1-2 Rain (.1-1 inch)
3-4 Sleet
5-7 Snow (1d6 inches)
8 Snow (3d6 inches)

Nightal (December)
Average Daily Temperature
High: 34
Low: 18
Fog: 80%
Cloudiness: 1d20
Precipitation: 60%

D8 Roll Result

1 Rain (.1-1 inch)
2 Sleet
3-6 Snow (1d6 inches)
7 Snow (3d6 inches)
8 Snow (3d10 inches)

Variations within the Isles

The Moonshae isles do not have the same type of weather everywhere at the same time, though the area is small enough that a general weather pattern can be assumed. However, if you want to determine specific variations, the following guidelines should help.

Altitude

The highlands tend to be a little colder on the average than the rest of the isles. Assume that any mountainous region is 2d6 degrees colder than the normal temperature established for the day. An area of high mountains (5,000 feet or higher) can be 3d6 degrees colder.

Latitude

The northern parts of the isles are often (50% of the time) colder than the average temperature by 1d10 degrees. Likewise the southern shores reach temperatures 1d10 degrees higher than the norm determined for a given day.

Thunderstorms

Whenever your determination reveals that the isles will receive an inch or more of rain during a day, that rain is accompanied by thunderstorms. While such storms serve more to add atmosphere than anything else, you can assume that characters exposed on a moor or mountaintop each have a 1% chance of being struck by lightning -- treat as a 6d6 lightning bolt spell. This increases to 2% for characters in a boat on open water.