Don't worry about bugs...........if you get a few and it is not an issue, predators will come and eat them within a week or two.
Spray stuff and you get rid of the predators too, upsetting the natural balance, then when you do get bad bugs, they explode in numbers before predators arrive.
I have been growing outdoors for 40 odd years and the amount of times I have had REAL issues with bugs, aphids mainly, can be counted on one hand. I do not classify a few bugs as an issue, I only am counting the times when bugs were in such numbers that they actually caused harm to the plants.
Marigolds and other flowering annuals help attract predators and the predators keep the bad bugs under control if you don;'t start interfering by spraying crap everywhere.
Rain on the other hand is an issue you can't control..........covering your plants with plastic sheets before it rains can help but is hard to do with big plants, so the best alternative is to plant strains that finish early or have a very short flowering cycle. Look at indica dominant strains, there flowering times can be as short as 6-7 weeks and hopefully they will be ready enough before the rains arrive.