Wunderground.com have email alerts, but they might be limited to US servere weather warnings.
I use Wundergound for my weather - good for stats junkies such as myself, or those what want a meaningful discussion of hurricane forecasts rather than the usual TV gloss.
However, I use their website (no advertising for $5/yr).
They also have some broader international weather forecasts/data.
gardening.stackexchange.com/users/69/winwaed
Below are some weather services you may wish to look into further (if you've not already): Weather reports for the UK: Weathercall by phone, fax and web - Paid service from the Met Office British Isles: Rainfall radar - Free online service from the Met Office.
If you click on a region, you will get more detailed information, including "Weather warnings overview".
The new National Severe Weather Warning Service - Free email service from the Met Office BBC Weather Service - Doesn't offer email service, but does offer free, Mobile access and RSS feeds.
Weather reports for the USA:
Weather Alerts & Inbox Weather - Free email service from The Weather Channel Mobile & Downloads - Free apps from The Weather Channel WeatherBug Mobile - Free and paid Mobile apps from WeatherBug Desktop Weather Products - Free Desktop apps from WeatherBug Email Alerts & Updates - Free email service from National Weather Service Daily forecast & severe weather watches & warnings - Free email service from AccuWeather
Worldwide weather reports:
WeatherTrends360
- Offers free email service, but requires free membership Mobile & Downloads - Free apps from The Weather Channel WeatherBug Mobile - Free and paid Mobile apps from WeatherBug Desktop Weather Products - Free Desktop apps from WeatherBug BBC Weather Service - Doesn't offer email service, but does offer free, Mobile access and RSS feeds.
Google maps
"Weather" - Free overlay to Google maps, powered by Weather.com Rain or shine, see the weather in Google Maps Weather services I personally use (living in the USA): The Weather Channel Mobile App
- Hourly, Daily, 36 Hour & 10 Day weather, plus Alerts WeatherBug Mobile App -
Hourly, Daily & Weekly weather, plus Alerts Missouri Botanical Garden on Twitter - Freeze warnings
The above weather services come from: Asking a few gardening experts and weather companies/services on twitter for their recommendations.
An internet search.
Personal experience with some of those services.
gardening.stackexchange.com/users/394/Mike Perry
I think I've found a winner! "
If this then that" is a website that lets you specify an action to take based on some trigger event.
They have weather triggers available, and email/SMS actions.
Here's my ifttt recipe for email frost alerts.
I just barely set it up, so I don't yet know how reliable it will be.
SMS is left as an exercise to the reader...
gardening.stackexchange.com/users/51/bstpierre
You can try Weather Underground .
This is one of the best sites for weather information and I always rely on this to plan my road trips.
I've found the information very comprehensive and the layout & navigation thoroughly satisfying.
If you sign up as a paid member ($10/yr, although there are free memberships with lesser features), you'll have access to email forcasts & updates.
From their sign-up page: Our new email forecast and alert service is included with every membership.
As a member, you select cities where you want weather updates, and we'll send you alerts immediately after they are issued by the National Weather Service.
Forecasts are reformatted for text, or html devices, and can be sent whenever you choose as a paid member.
I'm not sure if the information for other countries will be as comprehensive as that for the US, mainly because different weather stations report information selectively.
But it might be worth a try.
gardening.stackexchange.com/users/109/Lorem Ipsum
I could not find a service
so I have made one, http://frostalertemail.com
(UK only).
gardening.stackexchange.com/users/1026/Adam Foster
I had the same problem and couldn't find a solution..
so I developed ColdSnap!
for Android..costs less than a packet of seeds (and now does high temperature warnings too).
gardening.stackexchange.com/users/1066/Antony Cook
I've developed www.ifweather.com for managing custom weather alerts and sending email just like you describe.
It isn't free, but it's the best option for managing many alerts for more than one location that I've found.
It currently has the ability to watch the forecast for temperature and precipitation conditions.
When the conditions you specify are satisfied it sends you an email.
You can schedule when you'd like to receive emails too, so you won't get pestered at inconvenient times.
It does work in the UK as well as other countries.
gardening.stackexchange.com/users/13584/Contraptor
What's the best way to get warned if there's going to be a frost? Is there website or online service which will email me?  My priority would be a service which emails only in the event of frost warnings but I guess a year round daily email with min/max forecasted temperatures for my postcode would be fine.  I'm in the UK. I did sign up with one UK frost alert service before last winter (sorry, can't remember which one) but never received any emails.
How can I best get an alert if overnight frost is predicted?
gardening.stackexchange.com
<weather><resources><frost>
gardening.stackexchange.com/questions/1301
gardening.stackexchange.com/users/99/Tea Drinker
Try Weather Underground or Wunderground.com for weather alerts. Wunderground.com have email alerts, but they might be limited to US. You can also try  Weather Underground . The following have also been developed  www.ifweather.com, http://frostalertemail.com  and ColdSnap.
Wunderground.com have email alerts, but they might be limited to US or You can try  Weather Underground . The following have also been developed  www.ifweather.com, http://frostalertemail.com  and ColdSnap.