Extech Instruments WTH600 - Wind Chill, Heat Index, Dew Point; Wind Chill & Heat Index

14 WTH600-en-US_v1.0 8/17
6
Strong breeze
39–49 km/h
Large branches in motion. Whistling heard in
overhead wires. Umbrella use becomes difficult.
Empty plastic bins tip over.
25–30 mph
22–27 knots
10.8–13.8 m/s
7
High wind
50–61 km/h
Whole trees in motion. Effort needed to walk against
the wind.
31–38 mph
28–33 knots
13.9–17.1 m/s
8
Gale
62–74 km/h
Some twigs broken from trees. Cars veer on road.
Progress on foot is seriously impeded.
39–46 mph
34–40 knots
17.2–20.7 m/s
9
Strong gale
75–88 km/h
Some branches break off trees, and some small trees
blow over. Construction/temporary signs and
barricades blow over.
47–54 mph
41–47 knots
20.8–24.4 m/s
10
Storm
89–102 km/h
Trees are split or uprooted, structural damage likely.
55–63 mph
48–55 knots
24.5–28.4 m/s
11
Violent storm
103–117 km/h
Widespread vegetation and structural damage likely.
64–73 mph
56–63 knots
28.5–32.6 m/s
12
Hurricane force
≥ 118 km/h
Severe widespread damage to vegetation and
structures. Debris and unsecured objects become
airborne.
≥ 74 mph
≥ 64 knots
≥ 32.7m/s
11. WIND CHILL / HEAT INDEX / DEW POINT
View the Wind Chill
Press the [INDEX] button repeatedly until the WINDCHILL appears.
Note: The wind chill factor is based on the combined effects of temperature and wind speed. The
wind chill displayed is calculated solely from temperature and humidity measured by the wireless
sensor.
View the Heat Index
Press the [INDEX] button repeatedly until the HEAT INDEX appears.
Note: Heat index is only calculated when temperature is 80°F/27°C or above, and based solely from
the temperature and humidity measured by the wireless sensor.
Heat Index Range
Warning
Explanation
80°F to 90°F (27°C to 32°C)
Caution
Possibility of heat exhaustion
91°F to 105°F (33°C to 40°C)
Extreme Caution
Possibility of heat dehydration
106°F to 129°F (41°C to 54°C)
Danger
Heat exhaustion likely
≥130°F (≥55°C)
Extreme Danger
Strong risk of dehydration / sun stroke