From Meg McGrath, Long Island Horticultural Research & Extension Center, mtm3@cornell.edu:
Downy mildew was found affecting cucumber in a commercial crop in Chatham-Kent, Ontario, last week. Fortunately only one crop found affected and only a few plants, which greatly decreases the potential for successful spread to New York. There was some risk forecast, but low, for successful spread to western and northern NY on 28 and 29 June.
Growers should be weekly checking their cucumber crops for symptoms and checking the forecast website for risk of pathogen spread to their crops plus reports of new occurrences. With rain forecast over next weekend, there is potential for increased risk of spread if wind trajectory is from Canada to N.Y. See cucurbit downy mildew webpage for information about management.