The current risk for cucurbit downy mildew (CDM) in New England, including southern NH, is moderate according to the CDM IPM forecasting model: https://cdm.ipmpipe.org/forecasting/.
…BUT…a tropical storm is moving up the coast and CDM is active in PA.
It is likely that the risk will be high by later today (Friday 7/10/2020) or tomorrow (Saturday 7/11/2020).
Cucurbit producers (cucumbers, melons, summer & winter squash) should have protectant fungicides for CDM on prior to the arrival of the storm. These are listed in the New England Vegetable Management Guide - go to the crops tab and select the appropriate cucurbit crop(s). Chlorothalonil or copper products (organic options) are protectant fungicides that most growers probably already have on-hand.
Monitor your crops after this system moves through. If you suspect you have CDM infections, Please take photos and submit them to email@example.com. Once CDM occurs in our area it will be important to switch from protectant fungicides to fungicides with specific activity against CDM.
The Extension Fruit & Vegetable team.