In recent years the lakes have had limited quantities of fish, and perhaps other foods, leading the inhabitants to believe sternly that what little they have, they need. For this reason, trade with strangers is frowned upon.
Edora's orbit enters an irregular shift where it briefly intersects an asteroid belt. Meteors enter the atmosphere and, usually, burn off before impact. This phenomenon is known as the "fire rain" by the local Edorans, and occurs each and every year.
Every one-hundred and fifty years (of thereabouts), however, the meteors impact the surface, sending clouds of naquadah into the air. For several days the outside is uninhabitable, and even indoor residences are in danger of impact.
A Hundred Days - Jack O'Neill is trapped on Edora for three months after a meteor strike buries the Stargate.
Shades of Grey - O'Neill returns to Edora under the pretense of staying there, only to turn around and dial a rogue N.I.D. base.