美丽的天气的英文表达方法有很多种，常用的有：

beautiful weather
fine weather
good weather
pleasant weather
nice weather

这些表达方式均来自英语中的形容词。例句如下：

"It's a beautiful day today. The weather is perfect for a picnic."（今天天气真好。这样的天气很适合野餐。）
"The fine weather has brought out a lot of people to the park."（好天气吸引了很多人到公园。）
"I hope the good weather continues for the rest of the week."（希望本周其余时间天气也都这么好。）
"It's such a pleasant surprise to wake up to such beautiful weather."（醒来发现天气这么好真是个惊喜。）
"I'm looking forward to a day of nice weather and relaxation."（我期待着一个天气好、放松的一天。）