Grade 5 Science Weather
Humidity
Water in the air is called Humidity.
If the air cannot hold any more water it is called saturated.
Things dry more slowly when air is saturated.
When saturated air cools, water condenses in droplets
making clouds or fog.
If cloud temperature drops, precipitation can form.
Dew is caused by moist air condensing on cold surfaces.
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Grade 5 Science Weather
A psychrometer can
measure the amount of
humidity in the air by
comparing temperatures
read by a dry thermometer
and a wet one.
Brainstorm
What different kinds of precipitation
are there?
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Grade 5 Science Weather
Precipitation:
When upper air cools it is not able to hold as
much moisture.
If temperatures are just cold enough to make
small droplets, rain or drizzle forms.
Hail forms when updrafts in cumulo nibus clouds carry
moisture up very high where it is cold. These drops freeze,
fall, and get pushed up again getting larger and larger each
time.
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Grade 5 Science Weather
If rain passes through
colder air on the way
down, it forms sleet and
freezing rain.
If air is cooled below
freezing, droplets turn to
ice crystals and make
snow.
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