When taking into account the millions of tonnes of CO2 released by Ejaffawhateveritis, probably about as much effect as a fart in a Force 10 gale.
Considering that Wx varies by the minute, never mind over a few days, attempting to make any sort of measurement or comparison would be thoroughly impossible, and as such any concluded "affect" or "variation" linked with the lack of air traffic would be extremely tenacious at best.
Also bearing in mind the amount of low-level VFR traffic over the past few days, and the increased traffic on roads and seas, it is impossible to judge any sort of effect.
What will be more interesting to study is how this affair will affect operators' maintenance costs... perhaps a few early returns to the workshop are in order...?
Smithy