You can determine how fast the wind is blowing by using the chart below. It provides useful information when you are out on the trail or observing the wind's impact from indoors.

The chart is a ready reference, but when outdoors remember that wind can present many dangers. Be aware that wind dehydrates you, regardless of air temperature; wind chill lowers your body temperature and can damage your skin or even blind you in a snow storm. Wind power increases exponentially compared to wind speed.

When hiking in windy conditions, always carry extra water and extra clothing, hat and gloves. Plan your route so that you are sheltered from prevailing winds and make sure you get to or build shelter before dark.

To supplement your knowledge, build an anemometer for accurate measurements and compare your observations to the chart below.

Speed of Moving Air Name What We Can See

0 mph (0 km/h) Calm Smoke rises

1-3 mph (1-5 km/h) Light air Smoke drifts

4-7 mph (6-11 km/h) Light breeze Leaves rustle

8-12 mph (12-19 km/h) Gentle breeze Leaves and twigs

13-18 mph (20-29 km/h) Moderate breeze Branches move

19-24 mph (30-39 km/h) Fresh breeze Saplings sway/white caps on water

25-31 mph (40-50 km/h) Strong breeze Large branches move

32-38 mph (51-61 km/h) Moderate gale Entire trees sway

39-46 mph (62-74 km/h) Fresh gale Twigs break/ walking is a challenge

47-54 mph (75-87 km/h) Strong gale Branches, street signs blow down

55-63 mph (88-102 km/h) Full gale Trees uprooted

64-72 mph (103-121 km/h) Storm force Structures damaged

73+ mph (122+ km/h) Hurricane force Widespread devastation