Does the microclimate change under the tarpaulin? Yes, probably. After all, that's the whole point. The temperature stays higher at night and during the critical morning hours. But it stays higher also in the days, which gives a kind of greenhouse effect. So, the question is whether to keep the tarpaulin on the vines all the time during the critical days? Or having the trouble of rolling it off in daytime and back again in the evenings?