Table: Random Weather
d% Weather Cold Climate Temperate Climate1 Desert
  1. Temperate includes forest, hills, marsh, mountains, plains, and warm aquatic.
01-70 Normal weather Cold, calm Normal for season2 Hot, calm
71-80 Abnormal weather Heat wave (01-30) or
cold snap (31-100)
Heat wave (01-50) or
cold snap (51-100)
Hot, windy
81-90 Inclement weather Precipitation (snow) Precipitation (normal for season) Hot, windy
91-99 Storm Snowstorm Thunderstorm, snowstorm3 Duststorm
100 Powerful storm Blizzard Windstorm, blizzard4, hurricane, tornado Downpour

Sometimes weather can play an important role in an adventure.

Table: Random Weather is an appropriate weather table for general use, and can be used as a basis for a local weather tables. Terms on that table are defined as follows.


Wind speeds are light (0 to 10 mph).


Between 0° and 40° Fahrenheit during the day, 10 to 20 degrees colder at night.

Cold Snap

Lowers temperature by -10° F.


Treat as rain (see Precipitation, below), but conceals as fog. Can create floods (see above). A downpour lasts for 2d4 hours.

Heat Wave

Raises temperature by +10° F.


Between 85° and 110° Fahrenheit during the day, 10 to 20 degrees colder at night.


Between 40° and 60° Fahrenheit during the day, 10 to 20 degrees colder at night.

Powerful Storm (Windstorm/Blizzard/Hurricane/Tornado)

Wind speeds are over 50 mph (see Table: Wind Effects). In addition, blizzards are accompanied by heavy snow (1d3 feet), and hurricanes are accompanied by downpours (see above). Windstorms last for 1d6 hours. Blizzards last for 1d3 days. Hurricanes can last for up to a week, but their major impact on characters will come in a 24-to-48-hour period when the center of the storm moves through their area. Tornadoes are very short-lived (1d6×10 minutes), typically forming as part of a thunderstorm system.


Roll d% to determine whether the precipitation is fog (01-30), rain/snow (31-90), or sleet/hail (91-00). Snow and sleet occur only when the temperature is 30° Fahrenheit or below. Most precipitation lasts for 2d4 hours. By contrast, hail lasts for only 1d20 minutes but usually accompanies 1d4 hours of rain.

Storm (Duststorm/Snowstorm/Thunderstorm)

Wind speeds are severe (30 to 50 mph) and visibility is cut by three-quarters. Storms last for 2d4-1 hours. See Storms, below, for more details.


Between 60° and 85° Fahrenheit during the day, 10 to 20 degrees colder at night.


Wind speeds are moderate to strong (10 to 30 mph); see Table: Wind Effects on the following page.

Rain, Snow, Sleet, And Hail




Rain reduces visibility ranges by half, resulting in a -4 penalty on Spot and Search checks. It has the same effect on flames, ranged weapon attacks, and Listen checks as severe wind.



Heavy Snow





Hail does not reduce visibility, but the sound of falling hail makes Listen checks more difficult (-4 penalty). Sometimes (5% chance) hail can become large enough to deal 1 point of lethal damage (per storm) to anything in the open. Once on the ground, hail has the same effect on movement as snow.


The combined effects of precipitation (or dust) and wind that accompany all storms reduce visibility ranges by three quarters, imposing a -8 penalty on Spot, Search, and Listen checks. Storms make ranged weapon attacks impossible, except for those using siege weapons, which have a -4 penalty on attack rolls. They automatically extinguish candles, torches, and similar unprotected flames. They cause protected flames, such as those of lanterns, to dance wildly and have a 50% chance to extinguish these lights. See Table: Wind Effects for possible consequences to creatures caught outside without shelter during such a storm. Storms are divided into the following three types.

Duststorm (CR 3)






Powerful Storms









One in ten thunderstorms is accompanied by a tornado.



Table: Wind Effects
Wind Force Wind Speed Ranged Attacks
Normal/Siege Weapons1
Creature Size2 Wind Effect
on Creatures
Save DC
  1. The siege weapon category includes ballista and catapult attacks as well as boulders tossed by giants.




Light 0-10 mph —/— Any None
Moderate 11-20 mph —/— Any None
Strong 21-30 mph -2/— Tiny or smaller Knocked down 10
Small or larger None
Severe 31-50 mph -4/— Tiny Blown away 15
Small Knocked down
Medium Checked
Large or larger None
Windstorm 51-74 mph Impossible/-4 Small or smaller Blown away 18
Medium Knocked down
Large or Huge Checked
Gargantuan or Colossal None
Hurricane 75-174 mph Impossible/-8 Medium or smaller Blown away 20
Large Knocked down
Huge Checked
Gargantuan or Colossal None
Tornado 175-300 mph Impossible/impossible Large or smaller Blown away 30
Huge Knocked down
Gargantuan or Colossal Checked


The wind can create a stinging spray of sand or dust, fan a large fire, heel over a small boat, and blow gases or vapors away. If powerful enough, it can even knock characters down (see Table: Wind Effects), interfere with ranged attacks, or impose penalties on some skill checks.

Light Wind

A gentle breeze, having little or no game effect.

Moderate Wind


Strong Wind

Gusts that automatically extinguish unprotected flames (candles, torches, and the like). Such gusts impose a -2 penalty on ranged attack rolls and on Listen checks.

Severe Wind

In addition to automatically extinguishing any unprotected flames, winds of this magnitude cause protected flames (such as those of lanterns) to dance wildly and have a 50% chance of extinguishing these lights. Ranged weapon attacks and Listen checks are at a -4 penalty. This is the velocity of wind produced by a gust of wind spell.


Powerful enough to bring down branches if not whole trees, windstorms automatically extinguish unprotected flames and have a 75% chance of blowing out protected flames, such as those of lanterns. Ranged weapon attacks are impossible, and even siege weapons have a -4 penalty on attack rolls. Listen checks are at a -8 penalty due to the howling of the wind.

Hurricane-Force Wind

All flames are extinguished. Ranged attacks are impossible (except with siege weapons, which have a -8 penalty on attack rolls). Listen checks are impossible: All characters can hear is the roaring of the wind. Hurricane-force winds often fell trees.

Tornado (CR 10)
