Store them in your freezer for better results. There are some formulae out there on how the bittering power holds up in hops, but you just have to go with the smell test to see how the aroma holds up. If you can, vacuum pack them. If you cannot, put them in a ziploc baggie and get as much air out as you can.
Hops can stay good for a few to several months in the freezer in a ziploc bag. They can stay good for several months to a year or more if vacuum packed.