[RPG] When are the seasons in the Forgotten Realms calendar


I'm planning on starting to run Waterdeep: Dragon Heist soon, and part of the premise is that since the city looks and feels different in different seasons (people are less likely to be milling about in the Winter, for instance), one should select a season that the adventure starts in.

When I take notes as DM, I like to track what is happening on which in-game day, so that as time passes I can tell when the holidays fall and just generally what's happening in the rest of the world while the adventurers are doing things.

Waterdeep, being in the Forgotten Realms, uses the Calendar of Harptos described in the DMG on p. 33 and in the Waterdeep: Dragon Heist book on p. 7. What I can't seem to find, though, is this: When do the seasons take place on the calendar?

Both those references say that the months "roughly correspond to the months of the Gregorian calendar". And well, it's a 365¼-day (on average) calendar, so that makes sense. So does that mean, that Spring, say, is from roughly the 21st day of Ches (the 3rd month) to the 21st day of Kythorn (the 6th month)? (This is assuming, of course, that Waterdeep is in "the North" and thus uses Earth's Northern hemisphere naming of seasons?) Given that there's a holiday named Midsummer after the 7th month, this seems like it would roughly make sense (at least if all of the population using this calendar follows Northern hemisphere naming).

I know that it won't really have any impact on our table's story, but I'd like to know when the seasons take place "officially" so I can pick when this adventure should start.

Best Answer

The solstices and equinoxes changed recently (1488 DR)

At the end of the Second Sundering, the traditional days of season changing shifted. The Sword Coast Adventurer's Guide has the details (pg. 15):

The worlds of Abeir and Toril drifted apart in 1487 and 1488 DR. In some places this change was accompanied by cataclysm, while in others the shift went without notice. Astronomers and navigators who closely watched the stars couldn't fail to see that there were nights when they seemed to hang in the sky. The winter of 1487–1488 lasted longer than normal. It was then noted that the solstices and equinoxes had somehow shifted, beginning with the spring equinox falling on Greengrass of 1488 DR. The seasons followed suit, with each starting later and ending later.

This shift in seasons has caused some sages, and the priests of Chauntea, to consider changing the marking of some of the annual feast days, but most folk counsel patience, believing that the seasons will fall back to their previous cycle over the coming years.

Assuming the spring equinox is now in the Greengrass holiday, you can assume the spring lasts until Midsummer, where the summer now begins. Somewhere near the end of Marpenoth marks the start of the autumn, which lasts until Midwinter, where the winter now starts.

Old calendar

If you, as the DM, want to use the old equinoxes and solstices to mark the seasons changing, you can look at the Forgotten Realms Campaign Setting from the 3.X edition of D&D, which includes the following image:

Seasons in Forgotten Realms