June was a great month in Beijing. The weather was warm, the flowers in full bloom and plenty of crystal-clear days - with blue skies and lovely white clouds.
I have loved being out and about, just soaking it all up. And all the more so since indoor public places across the city - including restaurants, cafes, bars and hotels - are now smoke-free.
On Wednesday, Beijing's new smoking-control law came into effect. The Beijing law is the toughest tobacco-control one in China to date. Smoking is prohibited in all indoor public places, as well as many outdoor public places such as kindergartens and schools. There are tough penalties for owners and managers of establishments which do not comply.
The Beijing government's work to enforce the law is off to a great start. Health inspectors have been out and about in force, supported by thousands of community volunteers.
If you break the law, you will pay a fine - dozens of businesses have been fined in the last couple of weeks alone. Beijing's residents are actively engaging in the enforcement effort too: several thousand complaints have been made via the anti-smoking hotline.
Alongside the official enforcement effort, I have been especially pleased to see various venues supporting implementation of the law; like the local bar near my house which used to allow smoking, where I saw a waitress firmly explaining to patrons that smoking indoors is no longer allowed.
Or the big, buzzing Chinese restaurant I took some visiting colleagues, where, when the staff discovered we were from the World Health Organisation (WHO), told us how pleased they were not to have to breathe in their customers' second-hand smoke any more.
It has also been great to see Beijing Capital International Airport join the leading modern airports in the world, like London Heathrow and Los Angeles International, by making indoor smoking rooms a thing of the past.
I think even those who doubted whether the law could or would be effectively enforced would have to admit to being pleasantly surprised.
And the international experience suggests that public support will increase over time, even among smokers themselves, as the public comes to realise the benefits of the law.
And with good reason: the benefits of smoke-free laws are substantial. Exposure to second-hand smoke is deadly. There is no safe level of exposure. Most people do not realise that second-hand smoke causes dangerously high levels of indoor air pollution.
The PM2.5 reading when just three people are smoking in a restaurant is likely to be around 600; five smokers, and the reading is likely to top 1,200 - far worse than the outdoor air pollution on even a heavily polluted day.
The war against outdoor air pollution is a complex, long-term task. Fixing indoor air pollution caused by second-hand smoke can happen overnight by making public places 100 per cent smoke-free.
Beijing has now taken its place alongside other great cities around the world in doing this - and the residents of Beijing are now breathing easier for that.