Outdoor activities are unfortunately difficult to guarantee when you visit a city with as changeable weather as Dublin. That said, when a mild day comes around or you get a great summer's afternoon there are heaps of ways to get out and see and city in a whole new light. Whether it's doing a Segway tour, hopping on a bike, taking a leisurely stroll around some of Dublin's historical streets or getting out of the city altogether there's plenty to get excited about.
Take the DART out to Howth and go for a walk around Howth Head, head out to the Phoenix Park and Dublin Zoo to catch the deer and more exotic animals basking in the sun. Take your time perusing the shops on Grafton Street or sit down with an ice cream in Stephen's Green. You can be sure that every single Dubliner around you will be making the most of the good weather and the mood on a sunny day is infectious in its excitement.
For those deciding to take a chance and head out regardless of the conditions: be sure to come prepared for the elements, it will make all the difference to your experience. Many of these tours are specifically designed to brave all conditions and rightly so or they'd be out of business.