Should I Bring an Umbrella Today?
Bring an umbrella when the chance of rain is roughly 40% or higher, or when rain is already measurably falling. Above about 25 mph of sustained wind an umbrella usually becomes unusable, and in snow or sleet it does not help at all; in both cases a hooded waterproof layer is the better tool. People differ on where the bother of carrying one stops being worth it.
The bands WhetherWear actually applies
These are the thresholds the app uses, not a rule of thumb written for this page. Read them against the chance of rain for the hours you will genuinely be outside, not the daily figure.
| Chance of rain | What it means | What to carry |
|---|---|---|
| Under 25% | Not worth planning around | Nothing |
| 25–40% | Possible; worth a glance before you leave | Umbrella if it is already in your bag |
| 40% or more | Likely enough to carry for | Umbrella |
| 60% or more | Expect to get wet without a plan | Waterproof outer layer, umbrella as well |
Measured precipitation outranks all of it. If rain is already falling, the probability stops being a question and the answer is yes regardless of what the percentage said this morning.
The two cases where a higher chance means LESS umbrella
This is the part a percentage cannot tell you, and the reason this question is not simply "is it going to rain".
- Sustained wind at or above roughly 25 mph. An umbrella in that much wind inverts, and holding one steady turns a two-handed walk into a one-handed one. WhetherWear stops recommending an umbrella at that point and asks for a hooded shell instead — not because the rain got lighter, but because the tool stopped working. Note that this reads SUSTAINED wind, never the gust.
- Anything frozen. Snow, sleet, freezing rain and wintry mix are all suppressed. Snow does not run off a canopy the way rain does, and the hand holding the handle is the part of you that most needs to be in a pocket. A hood and a waterproof shoulder are what actually keep you dry.
Both rules live in one place in the app, so the umbrella advice on this page, on the home screen and in the hourly plan is the same decision rather than three similar ones.
Why the daily percentage misleads
A daily chance of rain describes the whole day, and you are not outside for the whole day. A 30% day can be a certainty for the twenty minutes of your commute and irrelevant for the rest of it, and the reverse happens just as often.
The useful question is the chance during the hours you will actually be exposed, which is why WhetherWear reads the hours ahead rather than a single daily figure. What to wear right now covers the same shift in framing for the outfit as a whole, and what to wear in the rain covers the layers once the answer is yes.
Related questions
What chance of rain is worth carrying an umbrella for?
Roughly 40% or higher during the hours you will be outside. Below about 25% it is generally not worth planning around, and between the two it comes down to whether carrying one costs you anything.
Is an umbrella any use in snow?
Rarely. Snow does not run off the canopy the way rain does, and keeping a hand out to hold it costs you more warmth than the cover is worth. A hood and a waterproof outer layer do the job better.
How windy is too windy for an umbrella?
Around 25 mph of sustained wind is where most umbrellas stop being usable, and gusts can invert one well below that. At that point a hooded shell is the more reliable choice.
Should I take an umbrella or a rain jacket?
An umbrella keeps your head and bag dry without making you warm, which suits mild, still rain. A jacket wins in wind, in cold, and any time you need both hands. In heavy rain, most people want both.