Something like this?
mask = (avePrecipitation7Days<1) & (aveDailyTemp>2);
Indicator = strings(size(mask));
Indicator(mask) = "GO";
Indicator(~mask) = "no"
Question: what are your units? millimetres of precipitation ? Degrees Celcius? Is that "average" for temperature including nighttime, or is it the daytime high?
If those are millimetres and Celcius, then where I live, you would be selecting April 7th to April 14th, and October 14th to October 21st only. Before April 7th the mean daily temperature is too low; after April 14th the 7 day average precipitation is too high. Before October 14th the 7 day average precipitation is too high; after October 21, the mean daily temperature is too low.
Early April is considered to be a minimum of one month too early to plant crops here: the ground has not thawed yet, and there too much chance of a frost. Mean daily temperature does not tell you much about frost risk: our averge high for April is 10C but our average low (considering the whole month) is -2C .
