Qualification:
I worked at a busy drop zone for 10 years.
Just announce yourself on the airfield frequency about 5-10 minutes out
and they'll tell you what's going on, including which runway is active and how high they are jumping from - standard altitudes are 3000ft and 12,000ft AGL.
At our place it was really simple: left-hand for 34, right-hand for 16.
We landed everyone on the east side, and if we are dropping at 3000 all day you can just pop up to 4000 and be completely out of the way.
Under no circumstances make a cross-field pass as that's usually right in the middle of everyone else's landing pattern, and we don't carry radios.
If you are just passing by a 2km buffer is lots - no one is likely to be in the air that far away.
No reply usually means nothing in the air.
aviation.stackexchange.com/users/1632/paul
First of all, recurring DZ's have parachute symbols on sectional charts, so look for them!
The FAA regulations have this to say: Federal Aviation Regulation Part 105.25 requires that ATC be notified no earlier than 24hours before or no later than one hour before the parachute operation begins in Class E and G airspace.
Jumps in Class A, B, C and D airspace require an authorization from ATC.
This means that if you expect chute activity in the area, ask ATC!
Controllers are required to give traffic advisories to jump aircraft before the jump,and to issue advisories to all known aircraft that will transit the Class E airspace within which the jump operations will occur.
When time or the number of aircraft make individual transmissions impractical, advisories to nonparticipating aircraft may be broadcast on appropriate frequencies.
And as always, check the NOTAMS!
aviation.stackexchange.com/users/3048/Bassinator
Are there any particular frequencies to monitor besides the airfield frequency?
How would I know parachuting is happening besides any NOTAMs?
Here in Seattle, jump aircraft are usually talking with ATC (Seattle Approach).
The jump airplane will announce 5 minutes out and the when the jump occurs.
aviation.stackexchange.com/users/1520/Steve Kuo
In Europe, it's generally a good idea to be on the Flight Information Service (FIS) frequency, where you can receive information about active drop zones and/traffic information to the airplane performing the drop, as they need to call in on the FIS frequency and announce when they start the drop.
aviation.stackexchange.com/users/572/SentryRaven
I'm not a pilot.
I did attempt to get a parachute license, but stopped after a couple of jumps.
I jumped at two different drop zones.
(And I'm from Sweden)
I just thought I'd offer a view from the other side.
At the DZs where I jumped, the pilot always talked to ATC before takeoff, so I would assume that ATC will know of any parachute activity.
The parachutists will fall, so if you can stay above the plane that will drop them, you'll be fine.
Where I jumped, 4000 m was highest allowed altitude without oxygen, so no one jumped from higher than that.
The parachutists will want to land at or very close to their field.
During the freefall part, they don't really drift with the wind.
Chutes will typically be opened at about 1000 m, and from that altitude, they will drift significantly with the wind.
Thus, they will be dropped upwind, and will typically not move very far downwind of the field, especially not at high altitudes.
So, in order of simplest/safest: Fly above them Fly downwind of their landing spot
If you need to fly close to their field, the higher up you can be, the better.
This should perhaps be taken with a few grains of salt, but hopefully others can chime in if I've said something incredibly stupid. :)
aviation.stackexchange.com/users/3900/gibson
There are several airfields nearby where parachuting activities routinely take place. How far away is considered to be a safe distance from the airfield when flying past it en-route to another destination? Are there any particular frequencies to monitor besides the airfield frequency? How would I know parachuting is happening besides any NOTAMs?
What should a pilot do when flying in the vicinity of parachute jumpers?
aviation.stackexchange.com
<safety><general-aviation><parachute>
aviation.stackexchange.com/questions/9056
aviation.stackexchange.com/users/3670/Eric
Controllers are required to give traffic advisories to jump aircraft before the jump,and to issue advisories to all known aircraft that will transit the Class E airspace within which the jump operations will occur. In Europe, it's generally a good idea to be on the  Flight Information Service  (FIS) frequency, where you can receive information about active drop zones and/traffic information to the airplane performing the drop, as they need to call in on the FIS frequency and announce when they start the drop. If you are just passing by a 2km buffer is lots - no one is likely to be in the air that far away.   The parachutists will fall, so if you can stay above the plane that will drop them, you'll be fine. In terms of location, a 2-km buffer should be sufficient if you are just passing by. Never make a cross-field pass. Stay above the plane dropping the parachutists. In terms of information sources, controllers will issue advisories to aircraft due to pass through the airspace where the jump operations are taking place. Pilots should also check the NOTAMS. In Europe, you should be on the Flight Information Service frequency to receive information about drop zones and timing of drops. You should also look for parachute symbols on sectional charts to identify recurring DZs.
In terms of location, a 2-km buffer should be sufficient if you are just passing by. Never make a cross-field pass. Stay above the plane dropping the parachutists. In terms of information sources, controllers will issue advisories to aircraft due to pass through the airspace where the jump operations are taking place. Pilots should also check the NOTAMS. In Europe, you should be on the Flight Information Service frequency to receive information about drop zones and timing of drops. You should also look for parachute symbols on sectional charts to identify recurring DZs.