[Lost Nutz Garage]

If you are in an area where your garage can get below freezing - be careful with any equipment that might retain water in an enclosed space.  Cooling coils, pumps, water filters can be damaged if frozen.  Ask me how I know. 

[EHall]

I live in PHX. My new setup gets stored in the garage but the majority of my equipment is in a closet in the house. The heat here will literally ruin certain things if you store it in the garage. I've also got camping/hunting gear in the house so it won't get ruined. where you store things really does depend on where you live. the more extreme your environment (regardless of heat or cold) the more I would say store certain things in the house.

[reverseapachemaster]

I would keep hops and yeast in as controlled of cold/cool temperatures as possible. I wouldn't worry about temperature with grain as long as you can keep out humidity. Keep in mind that grain grows in the summer in full sun and then sits in massive grain silos on farms, maltsters and breweries in the weather on a regular basis. Keeping grain at room temperature is not a big deal. However, you should keep grain in an animal defensive vessel so you don't have mice eating and defecating into your grain.

Your equipment will be fine at most temperatures. I wouldn't be so worried about heat unless you live in the desert but I would be worried about having your plastic or rubber get below freezing because those cold temperatures can over time cause small cracks and brittleness that will cause them to split or break. I'm sure plenty of people will point out that they keep equipment in garages that get well below freezing but it would not be my preference.