It is a combination of rainfall, temperature, wind, sunshine and air humidity which affects your garden from day to day.

Rainfall
There is no distinct rainy period in UK but Oct-Jan is usually the wettest period, with the Thames Estuary usually one of the driest areas and the mountains of Wales, Scotland, and the Lake District being the wettest.

Temperature
Winter nights with clear skies can be very cold, and prolonged freezing conditions can cause normally hardy plants to suffer.

High summer temperatures are necessary to ripen tomatoes, sweetcorn, and many fruits from warmer climates.
Hot weather with 27°C and above (80°F) has its drawbacks - soils dry out quickly, bloom life is shortened, transplanting is made difficult and the germination of some seeds (e.g. Lettuce) is impaired.

Wind
Gales are well-known for their destructive effects such as broken branches or knocked-over pots, but you should also be aware of persistent wind effects which are less well-known.

TIP: For exposed sites, windbreakers may be necessary but you should try to avoid using a solid screen.

Things to know about the wind:
- Negative effect: A solid screen (wall/closed fence) creates down-draughts on either side, which may harm plants.
- Positive effect: A hedge gently reduce wind speed for a distance of 15-30 times its height.

Frost
Plant growth can come to a premature end because of a late spring frost, which is most damaging of all.  Frost occurs when the temperature falls below 0°C (32°F).  It is damaging to plants because of  water becoming unavailable to plant roots and a rupture in the structure of sensitive plants.  These risks are linked with the severity and duration of the frost and the constitution of the plant.

These illustrations will give you a rough idea of the earliest and latest frosts during the year:

TIP: warning signs for frost:

- clear evening sky
- wind coming from the north decreasing at nightfall
- previous dry days

Dangers are minimised for a plant if:
- there are branches above or other plants around
- heavy soil below
- nearby coast

TIP: avoid planting delicate shrubs or fruiting trees if you live in an area most likely to suffer from frost, unless you protect them from winter damage.

You are probably also aware of the classification of plants between hardy, half-hardy and tender. But what does it mean in relation to the frost period?

Hardy plants: will survive during the period of frost (autumn to spring).
Half-hardy plants: are killed if left unprotected outdoors.
Tender plants: generally cannot survive outside, should be kept inside (greenhouse or indoors).

Frost pockets
One last piece of information you need to know about frost is "frost pockets".
They can occur anywhere but usually in an area prone to first and last frosts. When frost covers a garden, the cold air sinks to the lowest points, and cannot escape so it collects there.

The risks are bigger if your garden is:
- in a dip
- at the foot of a slope
- when a solid barrier is present on a sloping site

Damages to plants in such areas are very serious:
- growth starts later
- tender plants are easy targets for the frost
- planting half-hardy bedding a bit later than the "safer parts" of the garden will be necessary.

TIPS:
- You can spot frost pockets quite easily in the morning: look for areas which are not "defrosted" while the rest of the garden has.
- If your garden is half-down a slope, you can help the cold air escape by :
  - removing blockages
  - making gaps between fences or hedges.