i made a weather macro for foundry that takes the tables from BR & BOB, unifies them and makes weather a bit more predictable and dependent on the region & season (and how much fuss you want to have with weather in general)

https://www.mediafire.com/file/wd2r21c41qwu3iz/forbidden-lands-myweather_v0.1.zip/file

Intro:

“MyWeather” is supposed to give you a simple mechanic to generate some reasonable weather to spice up your journeys without taking up too much game time and brainpower. It works for all climate zones and seasons, from the frozen peaks of bitter reach to the scorching deserts that are not even discovered yet.

Weather is structured into temperature, clouds and wind which are all tracked individually. Clouds and Wind range from calm to storm and clear to dark clouds in 4 steps, the temperature from biting cold to scorching hot in 7 steps. You decide, based on region, season and infinite knowledge only a GM can have, what weather you expect, a “clear sky with mild breeze” for minimal negative effects on adventuring, “freezing temperatures with dark clouds and storm” during the dramatic search for the mountain pass in bitter reach, you name it. A table with inspiration will be provided. Expectations may be between two steps, during spring the expected temperature may be between cold and mild etc.

Once the expectations are set, you may roll a d6 for each weather element to see if it deviates from the expectation. Usually you roll once per day, but if you find the weather should change more or less often, feel free to adapt. We suggest you use three differently colored dice for the three elements and roll them together, white for wind, black for clouds and red for temperature. If the die shows a 6, the weather moves one step away from the expected weather, clouds and wind towards “more”, temperature towards colder. On a 1 or 2, the element moves towards the expectation or not at all, when the actual weather is already at expectation. In case the expectation is set between steps, the actual weather element will flip to the other side. In the example above, the actual temperature will alternate between mild and cold.

A table for the actual mechanical effects a weather phenomenon has is also provided. You are now all set to present your players with the added challenges your weather brings to the table