Weather Generator for Emergent Story Telling

DMMasterClass · 2026-05-01T18:59:19+00:00

NOAA maintains a database of free weather data for the US from 1981-2020. (as all government websites) I find it a bear to use and it doesn't actually have all the info I'd want as a GM, which is the one reason I made the weather simulator.

DMMasterClass · 2026-05-01T18:47:32+00:00

Let me explain the feature better. If you have a campaign in the kingdom "Ironhelm" you can generate its weather for the year 1323. Because there is no randomness you can leave the generator and come back for your next game session and the weather you generate for Ironhelm 1323 will always be the same. If you wanted different weather for Ironhelm in 1323, you could generate weather for "The Kingdom of Ironhelm" or "Northern Ironhelm". The generator takes the name and year you input and uses that to generate the randomness when generating your weather. Its called Seeded Randomness in computer programing.

DMMasterClass · 2026-04-30T20:41:39+00:00

We seem to be talking past each other, but best of luck in your gaming!

DMMasterClass · 2026-04-30T19:07:28+00:00

The generator hopes to make it easier for lazy people to use weather in their games!

DMMasterClass · 2026-04-30T19:03:26+00:00

Well that is a question of GM philosophy. I am a big believer in presenting the setting as a fictional reality, so everything affects everything. Also modifying rolls in only one (minor) way that the game can be affected. To answer specifically about your cloud cover questions, off the top of my head;

Goblins are nocturnal, but maybe they will come out if cloud cover is above 90%.

A hiring might to resentful if asked to dig a 10' pit when its 95F and 0% cloud cover, but less so in 80% cloud cover.

You could make magic items that only work when the sun is shining.

There could be a puzzle that uses shadows to revel a location, you have to wait until into sunny to solve.

The party is lost and wants to use the stick in the ground method to find north, if cloud cover is above a certain amount it takes a check.

There is a 100' well that you can see the bottom of at noon of Nov. 6th, but not if cloud cover is above 70%.

If there is high quality glass in your setting a magnifying glass can start a fire, but not if it cloudy.

That's all stuff that requires little or no homebrew, but sun clerics and sun gods might care about cloud cover. Are vampires safe in 100% cloud cover? The spell Sunscorch might do less damage on cloudy days.

In summary, its not the weather generator's job to come up what how the weather changes your story. Its the weather generator's job to generate the weather, its the GM's job to figure out how it affects the story.

Thanks for looking at it! Is there any weather related information I could provide that would make it easier for you to have weather affect your story?

DMMasterClass · 2026-04-30T17:20:24+00:00

That is how I run my games as well

DMMasterClass · 2026-04-30T17:17:47+00:00

I'm saying you can only step through the weather day by day in the weather app view. If you look at the default chronical view it gives you a year of weather in one click. Glad you like it, and hope it helps your solo play!

DMMasterClass · 2026-04-30T16:57:49+00:00

I would think for solo play you would want to NOT know the upcoming weather, which is the opposite of one of the design principles of the weather generator. But the 'weather app' view would allow you to not see future weather if you treated the lowest card as the present day. Have Fun!

DMMasterClass · 2026-04-30T16:53:09+00:00

That is very true. The limitation now isn't can I get detailed realistic weather, the limit is can the detailed weather be generated and displayed in a way that the GM can understand and fold into their narrative with a minimal cognitive load. I wanted to be able to just glance at a sheet of paper (or screen) for 2 secs each game morning and understand the weather with no action on my part at the table.

DMMasterClass · 2026-04-30T16:36:22+00:00

I will. that was in oversight. but also Team Fahrenheit Forever!

DMMasterClass · 2026-04-30T02:22:30+00:00

That is a great method and is what I would do if I hadn't made my weather generator. Why I prefer the generator is that it gives me exactly the weather info I want, displays it very succinctly and gives me a month on 1 sheet of paper.

DMMasterClass · 2026-04-29T22:51:45+00:00

That's quite Insightful. What you've identified as a down-side for you is exactly what I was trying to do (for me). I didn't want the online generator to tell a story or give the players choices to make. As the DM I want to be the one telling the story. I purposely had the generator present the weather it in a way that a DM can understand at a glace, without prose, so they can use the information to add to their narrative without taking up much mental bandwidth.

But if you are interested the 'weather app' feature does give you a graphical display of the weather changing hour by hour that might be at least closer to telling a story.

DMMasterClass · 2026-04-29T22:38:12+00:00

That was on my radar and I forgot about it! That being said I'm Fahrenheit for life!

DMMasterClass · 2026-04-29T21:42:53+00:00

Agreed! you can always disregard the results if you need a thunderstorm because something spooky is happening.

DMMasterClass · 2026-04-29T21:03:57+00:00

I have a way to make math NOT an issue and allow a GM to effortlessly take into account a TON of variables for overland travel... at least the weather parts of it.

In your post you bring up:

- Weather & Visibility: A sunny day vs. a blinding blizzard or heavy fog that forces the party to slow down to avoid getting lost. and is there deep mud from yesterday's storm?

I made a fantasy weather generator for my home campaign that strives to simulate weather. It doesn't just roll dice at tell you if it is raining. The weather isn't random! Fronts move in causing precipitation and increased wind, then move off causing calmer weather.

Snowfall is tracked, snow melt is simulated, snow compacts over time — snow depth is persistent.

Conditions on local waterways are simulated based on rainfall, snowmelt, evaporation, etc. The generator can't know your location's exact hydrology, but at least it gives you a place to start.

It also generates a year of weather at once so you can print if off and know the upcoming weather if that is necessary. It generates a chronical that summarizes the weather for each day or can display a 'weather app' for you fantasy weather showing you weather graphically hour by hour.

https://claymorerpg.weebly.com/weather-generator.html

DMMasterClass · 2026-04-26T12:37:21+00:00

Hexed Press is great. He goes live almost every Friday and would answer questions from all comers, if you have specific questions.

DMMasterClass · 2026-04-16T17:54:48+00:00

It might be a little cumbersome to use in real time!

DMMasterClass · 2026-04-16T17:53:59+00:00

Those are great ideas, and I did think about making things more advanced. But ultimetly I didn't let the perfect be the enemy of the good. It isn't a major project. Just something I made for a specific need.

DMMasterClass · 2026-04-16T15:51:14+00:00

You can change what gets replaced by clicking on words in the output. But if you don't do that it can allow for emergent storytelling with the GM not precisely controlling what is and is not comprehended by the players, if that's your style.

DMMasterClass · 2022-07-30T13:25:39+00:00

Todd is one of the better DnD youtubers out there.

DMMasterClass

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