Rain, rain go away (until after the wedding)

After 20 years of summer holidays in Scotland, you'd think I would be used to bad weather in July. "Don't be so pathetic," my husband, who is from Argyle, would say. "You don't need good weather to have fun," and we'd put on sou'westers, waterproofs and gumboots and trudge down to the beach for a hilarious family picnic.

After 20 years of summer holidays in Scotland, you'd think I would be used to bad weather in July. "Don't be so pathetic," my husband, who is from Argyle, would say. "You don't need good weather to have fun," and we'd put on sou'westers, waterproofs and gumboots and trudge down to the beach for a hilarious family picnic.

Occasionally we were lucky. I have photographs of wee Jim aged eight months, gurgling and cooing on the silver sand of Arisaig with a fish box rigged up on sticks to stop him getting sunburnt, because when the sun shines in the West Highlands it doesn't mess about. It's really hot. That's when we congratulate ourselves for not going on holiday to Italy or Spain, where you're pushed to find enough space on the beach to spread your towel.

The beauty of Scotland, we say smugly, is its remoteness, its emptiness, and the fact that, apart from the seals diving off the rocks on the other side of the loch, there is no one here but us.

Five years ago, when my youngest was seven, I got permission to take him out of his London primary school for the summer term and send him instead to the school on the island where we were building a house. It was the hottest summer that anyone in Argyle can remember. When I came down to London one weekend in June, all my friends said: "Gosh, where did you get that tan, Sardinia, Jamaica?" "No," I said, "Loch Linnhe."

In matters meteorological the Scots are far more philosophical than the English. If you don't like the weather, people on the island say, don't worry, just wait for 10 minutes – it's bound to change. And by and large it does, except for the memorable occasion when we set out to walk the Devil's Staircase, that seven-mile section of the West Highland Way that runs between Glencoe and Kinlochleven. There were six of us, and we'd barely being going half a mile before the heavens opened. Forget buckets, stair rods, cats and dogs. That downpour would have awed the monsoon-hardened natives of Bengal. Our clothes became so waterlogged that in the end we found it easier to take most of them off and carry them.

Looking out of the window now, I'm reminded of that sodden afternoon on the Devil's Staircase. I'm not in Scotland. I'm in leafy Killinghurst, just off the road to Petworth, where this time tomorrow 130 guests will be converging on the lawn of my mother's cottage to celebrate a second daughter's wedding.

For the first last year, we had the only rain-free Saturday in June. No, it wasn't luck. It was faith. Two weeks before the wedding, a friend sent me a small package. It contained a statue of a little boy about the size of a chess piece, richly attired with a golden crown on his tiny head. This, wrote my friend, was the Infant of Prague who, if I put him in a safe place in the garden of the cottage and prayed to him, would bring me good weather for my daughter's wedding. She was right. The sun not only shone, it positively blazed, and as they drank champagne and strolled along the flower-fringed alleys, everyone agreed that Gertrude Jekyll could have learnt a thing or two from my green-fingered mother.

This year the same friend sent me another Infant of Prague, if anything even more gorgeously ornamented, wearing a red coat instead of last year's blue one and carrying what looks like an orb in one hand. He's been safely in situ for a week, though at one stage he was in danger of being swept away by a flash flood.

I've prayed, God knows I've prayed, but when the contractors came this morning to put heavy-duty sides on the marquees and lay rubber mats on the mud I started to panic. It will be all right, friends assure me, there's still 24 hours to go. Certainly the forecast says we're due a bit of sunshine today. And if my prayers aren't enough, surely when you add them to all those with Wimbledon tickets for the ladies' final we must be in with a chance.

What I'm really worrying about is my hat, a glorious confection of cerise tulle with about as much resistance to water as Dawn French to a Terry's Chocolate Orange. That's probably it – the Infant of Prague knows I have faith, but he also sees my pride. I'd better ditch my peacock finery and settle for something simple that won't detract from the other guests. Where's that sou'wester I wore on the road to Kinlochleven?