Weather Data Arrives in m/s and America Reads mph
Open almost any raw weather product — a global model grid, a research buoy feed, a wind turbine's power curve, a drone's specification sheet — and the wind is in meters per second. Open the forecast the same data ends up in, anywhere in the United States, and it is in miles per hour. Somebody has to make the jump, and it usually happens several times before the number reaches the public.
The factor is not a round one, which is exactly why estimating it by eye goes wrong: doubling is a familiar shortcut and it undershoots by more than ten percent.
Who Makes This Jump Daily
Broadcast Forecasters
Wind Energy Analysts
Drone Operators
A Shortcut Worth Knowing
Multiply by two and add ten percent: 15 m/s gives 30 plus 3, or 33 mph, against a true 33.6 mph. It stays within half a mile per hour up to storm strength, which is close enough for a conversation and not close enough for a published figure.
Converting a Sensor or Model Value
Raw data rarely arrives as a tidy whole number, so the field accepts as many decimals as the source gives and both sides update together.
Type the m/s value exactly as reported
Awkward readings such as 12.7 or 8.35 go straight in, comma or dot, with no rounding needed beforehand.
Read the mph value while you type
The result updates on every keystroke, so stepping through a column of hourly values is quick even without pasting them in bulk.
Reverse it to check an instrument limit
Equipment ratings are metric. Swap the fields, enter the mph forecast and see whether it clears the m/s figure in the manual.
Reach knots when the source is marine
Buoy and aviation reports use knots. The searchable dropdowns let you compare all three units without leaving the card.
Hurricane Categories in m/s and mph
The Saffir-Simpson scale is defined in miles per hour, using a one-minute sustained wind at ten metres above the surface. Model and satellite data describing the same storm arrive in m/s, so this table is the bridge between the analysis and the headline.
| Category | Sustained wind (mph) | In m/s | Typical damage |
|---|---|---|---|
| Tropical storm | 39–73 mph | 17.4–32.6 m/s | Branches down, power flickers |
| Category 1 | 74–95 mph | 33.1–42.5 m/s | Roof, siding and gutter damage |
| Category 2 | 96–110 mph | 42.9–49.2 m/s | Major roof damage, trees snapped |
| Category 3 | 111–129 mph | 49.6–57.7 m/s | Devastating, water and power lost |
| Category 4 | 130–156 mph | 58.1–69.7 m/s | Walls fail, areas uninhabitable |
| Category 5 | 157 mph and above | 70.2 m/s and above | High share of framed homes destroyed |
Turbine engineering uses the lower half of the same range. A large machine starts generating around 3.5 m/s (7.8 mph), reaches rated output near 13 m/s (29.1 mph) and shuts down to protect itself at about 25 m/s, which is 55.9 mph — well below any hurricane category, and a reminder that the interesting wind thresholds are not always the dramatic ones.
Sensor Decimals Preserved
Results carry up to eight decimal places, so a reading of 7.35 m/s does not get flattened before you have finished with it.
Check an Equipment Limit Backwards
Swapping the direction turns an mph forecast into the m/s figure printed in a turbine, drone or crane manual.
Clipboard Ready for Graphics
The copy button hands over the number alone, which is what an on-screen graphic template expects to receive.
Three Wind Dialects Side by Side
m/s, mph and knots all sit in the same searchable list, covering models, public forecasts and marine or aviation reports.
Wind Data Questions Answered in mph
Why do weather models output wind in m/s?
Because the physics inside them is SI throughout, and because the output is shared internationally. Wind is also stored as two components, one eastward and one northward, and keeping those in m/s means no conversion factor has to travel with the data.
What does a 10 m/s wind feel like in mph?
22.4 mph — a fresh breeze that raises whitecaps on a lake and makes small trees sway. It is the point at which patio umbrellas start moving and light drones begin working noticeably harder to hold position.
At what m/s value does hurricane strength begin?
33.1 m/s, since the Category 1 threshold is 74 mph. Data published in whole m/s often shows 33 m/s for a storm reported as a hurricane, which is the same wind rounded on the other side of the conversion.
Are wind turbine ratings given in m/s or mph?
In m/s, worldwide, including on machines installed in the United States. A cut-out speed of 25 m/s is 55.9 mph, so a turbine can be standing still on a day the local forecast calls merely windy.
Why is the reported gust higher than the model's m/s value?
They are different quantities, not different units. Model output is usually a mean wind over an averaging window at ten metres height, while a gust is a brief peak of a few seconds. Converting the mean will never reproduce the gust figure.
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