You know it's cold when....

[Piwoslaw]

Last week was COLD here: no more than -15*C during the day, and as low as -30*C (-22*F) at night. The Vistula river froze over in Warsaw, something that's never happened during my lifetime:

(picture: Krzysztof Balcerzak)

The small stream of unfrozen water is from a warm sewage pipe.

[tasdrouille]

You know it's cold when the idle speed control actuator makes you car rev at 2500 rpm for a minute when you start it.

[Bicycle Bob]

You know it's cold when those weather reports from Maine look pretty nice. Of course, the humidity is worse there. Also, when you don't dare touch a door knob with a bare hand, because the snow squeaks in soprano. And when you have lots of time to knock the snow off your shoes before it starts to melt, the frost on your beard reaches your ears, and you have chunks of ice falling off your moustache after ten minutes indoors. I know it has been cold when air that does not sting feels great.
A friend went winter camping with the militia, and said he was woken up by the Kiki bird. It goes "Ki-Ki-Ki-rist it's cold!"

[wagonman76]

You know it's cold when the chimney is on fire in the house and the pipe outside is still below freezing.

[Piwoslaw]

You know it's cold when...
The closest you get to being 'warm' is when you are shovelling snow (again).

[Nevyn]

......when your 400W block heater can't get the car above 30*C (86*F).

[Mustang Dave]

You know it's somewhat cold when one of the hard-core locals at the local ski area complains about the cold. It wasn't THAT cold today. It was about 15°F with light winds.
I've skied there when it was 0°F with 50 MPH winds at the top. THAT was a cold day.

[Piwoslaw]

You know it's cold when...
... Your plastic grille block becomes so brittle that it brakes.

... The chains on your tires start to thermally contract.

... "Nonfreezing" windshield fluid starts to freeze.

... Your neighbor's car doesn't start in the morning, so you help to push it. Once it gets started it drags you because your gloves froze to the trunk lid.

... Your 7 year old battery finally starts to show the first signs of old age.

... You park your car for only 10 minutes and the engine is 10°C/18°F cooler when it starts again.

... When an engine off coast of only 2km cools your engine by at least 5-8°C.

[Piwoslaw]

You know it's cold when...
... An IR thermometer pointed at your car's chassis shows

It's in °C, but at that temp it doesn't make much difference It showed -41°C (-42°F) just before I got the camera to work (the first set of batteries froze).

So I bundle up and go to take a train, but it's delayed because a rail cracked next to my station.

You know it's cold when...
... The polar bears in your back yard decide to hibernate till April.

[tjts1]

I know its cold when I don't have to use the AC.