It will snow.

à snow falls from the sky

It will hail.

à small balls of ice fall from the sky

It will freeze.

à very cold, the temperature falls below the freezing point (0°C)

It will be chilly.

à cold but not very cold

Everything will be white with frost.

à white powder (frozen water) that covers the ground and plants

There will be some sleet.

à a mixture of snow and rain

There will be a blizard.

à a storm with a lot of snow and strong wind

The air will be crisp.

à it feels cold, but in a pleasant way; fresh and clear

It will be lovely weather.

à very sunny and good

It will be fair.

à nice weather, especially used in weather forecasts

It wil be sizzling hot.

à extremely hot (also: boiling, burning, baking)

There will be a heatwave.

à a long period of unusually hot weather

It will rain.

à rain falls from the sky

There will be some showers.

à short periods of rain

It will be pouring with rain.

à very hard rain

It will drizzle.

à a little rain, with very small drops

It will be cloudy.

à a lot of clouds in the sky

It will be grey.

à cloudy and not bright

It will be overcast.

à very cloudy and dark, it's likely to rain

There will be a sunny spell.

à a very short period with some sunshine

There will be sunny intervals.

à short periods of fine weather between cloudy, rainy weather

There will be a thick fog.

à cloudy air near the ground which is difficult to see through

There will be a mild wind.

à almost no wind

There will be a moderate wind.

à a bit of wind, but not too hard

There will be a strong wind.

à a lot of wind

There will be a summer breeze.

à a nice warm wind, not too hard

There will be strong gales.

à a very strong wind

There will be a hurricane.

à a violent storm with extremely strong winds