Rain
Low rainfall means seedlings, pot plants, and new plants or lawns are particularly vulnerable to drought.
There are often brief summer showers in July, sometimes heavy and thundery. Freak hailstorms have even been reported. But this short, sharp fall of water will run off and evaporate quickly, without being absorbed into the soil. Donot assume that brief rainfall will make it unnecessary to water the garden.
Sunshine
Light levels are good in July, although not as high as in June, as we are past the summer solstice. The north and west of England receive on average about 160-165 hours of sunshine, and the south, south-east, and south-west get about 175-180 hours.
Temperature
Some of the hottest days of previous years have been in July. The afternoon temperatures in the south of England can reach 29-32°C, while in the north and west, and in Wales, Scotland, and Northern Ireland, they can reach 27°C.
Ventilation and shading should be considered in the greenhouse and conservatory, especially on clear days when the heat of the sun is unimpeded by cloud.
Clear days will also see the most water evaporation from soil and ponds, and the most uptake of water by plants.
Wind
Hot, sunny July days are usually accompanied by light south-westerly or westerly winds. It is a good idea to ensure plants are well staked, even during still periods, as showers and brief gusts can be enough to damage stems.