Often, a problem I encounter is that in rainy seasons the rains come really suddenly. It is really difficult to find stores or pedestrians who are kind enough to lend an umbrella to a stranger (in this case, the poor stranger is me), and I end up getting stuck under a random canopy waiting for the rain to stop.
What can I do to get home quickly (or make progress doing so) without an umbrella and avoiding getting wet when I'm stuck in the rain?
Order a taxi to take you straight to your home. For this case, I keep telephone numbers of trusted taxis in my pocket. While waiting, eat a sandwich in the nearest cafe :)
Another variant:
I always wear a rain jacket with a hood outside (if I feel that there will be or is a rainy weather), like this
If you have such a jacket, then pull its hood on your head and zip your zipper.
And, by the way, if you are planning to use newspaper (non-glossy one), I wouldn't recommend to do it in the heavy rain due to the terrible personal experience. I am not saying this about magazines - they are quite good "tool" to "harbor" from rain.
Run, but be careful not to go too quickly, so that you don't slip. Try and stay under cover as much as possible (trees, awnings, someone else's umbrella).
Try and judge which way the wind is blowing. Then, even if you're not perfectly under cover, staying behind buildings might block some rain.
When you are in regions with regular rain, seek a place where you can stay for 5 minutes. After that the rain will stop wetting you instantly and you could use anything that covers your head (newspaper, jacket) to help against the wetting.
When you are in regions where sudden bursts of monsoon hit you, do observe the locals. If the street suddenly empties seek shelter quickly. A heavy downpour of rain will rain through most umbrellas anyway but lasts only 30 minutes or so. Wait it out.
If you have capacity to prepare for this situation pack a fold able raincoat into your backpack / jacket (whatever you have with you all the time). So then, even if you forgot your umbrella you have something waterproof with you.
In doubt: Running faster keeps you drier until the point where you start to slip or are wet through and through anyway.
Run as fast as you can to the nearest shelter without risking slipping.
From this BBC article, the equation of wetness (roughly) is:
W = p*[a * V_r / V_p + A]*D
Where W is wetness, p is the rain density, a is your "top-side" surface area, A is your "front-side" surface area, V_r is rain velocity and V_p is your own velocity. D is distance to the nearest shelter.
The result is that by maximizing V_p the total wetness reduces.
Of course if there's no shelter, the equation suggests not moving at all and waiting out the rain:
W = p * (a * V_r + A * V_p) * t
where t is the time spent in the rain.
Modern technology lets you hack this problem away!
In most parts of the world, weather forecasting is performed at least daily, and in many places you can get accurate hour-by-hour predictions. One of the main things they try to predict is whether there will be precipitation. As you can see from this study, the best predictors as of 7 years ago were bordering on 90% accuracy one day off, and it's only gotten better since. You can check forecasts on any device with an internet connection, such as a computer or a smartphone. You can also check them via TV or radio if those are more readily available.
That means that 90% of the time, you can avoid this trouble by checking the weather forecasts, which should not take more than a few seconds in the morning. If there's anything more than a 10% chance of rain, just bring an umbrella and you've pre-hacked the system to avoid your troubles. You can do better by checking closer to the time you need to be outside, since forecasts generally do better the closer you are.
In addition, if you frequently go to certain places other than your home (e.g. your office) you can leave an umbrella in each of them. This will allow you to check right before you have to go outside again, which gives you the benefit of the most up-to-date forecasts. The only downside is that you'll have to carry the umbrella back with you, but that's not anywhere near as bad as being caught in the rain without one.
As an alternative to an umbrella, you could keep a poncho in your pocket. Disposable ponchos are available for as low as 1 USD and easily fit in even a small pocket. A garbage bag with a hole for your head will work as well if you're desperate. These are good options if umbrellas are not acceptable for any reason.
This answer cannot account for your transportation. If you ride cabs, drive yourself or use the bus, I cannot account for that. Because these factors differ everywhere
My methods:
Carry a reasonably water proof bag with you. If you have a purse or other handbag you can use that to cover your head at least and deflect some of the water from your body.
Carry a garbage bag. A large garbage bag can be used to cover your clothes and stop them from getting you very wet, also they are small so you can carry them anywhere. Alternatively, even though this is not a hack you could use some waterproof smocks(sort of like this, but there are smaller ones).
Newspaper or magazine. Holding these over your head makes them get wet and not you.
Try taking your clothing off. This is very undesirable, but you can undress as much clothing as is decent and put them in any bag you have. Or take a shirt you have off(if you can) and drape that to protect the other clothing.
Or in the words of Lifehacker.com: Run for it.
you will catch less rain if you run faster, but the angle of your body has an effect as well because of the direction of the rain. Leaning forward can improve your chances of staying dry. This is great, but my concern would be more of slipping and falling or running into something accidentally than getting wet in this case.
So try to:
Angle away from the rain
Not slip
Run very fast
Additional Info
Plan ahead: Bring a umbrella or check the weather. Some apps can give you alerts.
For me it depends of my motivation but you can:
I keep a plastic/waterproof map in my backpack/bookbag at all times. You can get them at Trail Illustrated or other vendors. Some of our local county parks have them, too. They are compact, tough, lightweight and can be easily unfolded and held over my head when it rains. They are not perfect; but, they can get me to my car parked at the far end of the parking lot. (And, I wear my backpack in front of me.) A garbage bag might work, too. But, make sure you get a nice thick one. But, the unfolded map blocks a lot more rain.
To avoid rain, make sure to keep a jacket or a plastic bag along with you (avoid technology devices).
If you are not going home, bring a spare change of clothes and put it in a plastic bag. Make sure to leave your home at a reasonable time so that you get time to change your dress before school or work.
If none of the above-said equipment is reachable, then I would suggest that you run and bolt it, praying that you don't crack your head open and hoping that you don't get wet.
Improvise an umbrella by pulling your jacket up over your head or finding a discarded newspaper. Warning do not use your cell phone for an improvised umbrella it is not large enough and you may ruin your phone. Do not improvise an umbrella with a hair dryer as they are clearly marked "not for use in showers".
