Whilst lithium and eneloops have much to commend them, standard alkalines have the advantage of low cost.

IMHO the best way to store alkalines is in a "cooler" which of course does not really cool at all.
Articles placed in such a thermally insulated box will reach the same average temperature as the suroundings, but will be protected from extremes of temperature.

Reputable alkaline cells keep for 7 years from production, or about 5 or 6 years from purchase.
The risk of leakage is reduced by storing at an even temperature.

I keep cells in the suppliers packaging, and have had very few leak.

Despite the simplicity of only one cell size, it might be worth stocking D cells in addition to AA.
D cells contain about 7 times more energy than AA for only about twice the price, and are therefore preferable for any longer term emergency such as the aftermath of a bad earthquake.