This is not the first time iOS device users are facing Wi-Fi connectivity issues after upgrading to the latest iOS 5/iOS 5.0.1 software update. Users have reported similar issues with Wi-Fi connectivity after upgrading to iOS 3.x and iOS 4.x software update as well. If you’re facing any of these issues, you can follow these tips to see if one of them resolves the issue until Apple releases an iOS software update to fix the issue:

Basic Troubleshooting:
  • Launch Settings app
  • Tap Wi-Fi
  • Turn Wi-Fi toggle off and then on again
Renew IP Address: If this doesn't work then try to renew IP address, which may be required if you are using a larger wireless network.
  • Launch Settings app
  • Tap on the Wi-Fi network that you connect to from the list
  • Scroll down and tap on the Renew Lease button
Forget This Network: If renewing IP address doesn’t resolve the issue, try establishing a fresh connection with the Wi-Fi network by using the Forget This Network option. Please note that this will clear your current Wi-Fi network settings, including saved Wi-Fi passwords.
  • Launch Settings app
  • Tap on the Wi-Fi network that you connect to from the list
  • Tap on the Forget This Network button
  • You will be prompted with a message that your iOS device will stop automatically joining this network. Tap on the Forget button.
  • Go back to the list of Wi-Fi networks, try to locate and join the Wi-Fi network again.
If this doesn’t help try restarting your iOS device. Restart iOS Device:
  • Press and hold the Sleep/Wake button until "slide to power off" slider appears. Slide your finger across the slider and iOS device will turn off after a few moments.
  • Turn iOS device on by pressing and holding the Sleep/Wake button until the Apple logo appears.
Reset Network Settings: If restarting your iOS device doesn’t resolve the problem then reset all network settings. Please note that this will clear your current cellular and Wi-Fi network settings, including saved networks, Wi-Fi passwords, and VPN settings.
  • Launch Settings app
  • Tap General
  • Scroll to the bottom of the screen and tap on Reset
  • Tap Reset Network Settings
  • When the device restarts, try to locate and join the Wi-Fi network again.
Click here to enlarge Please let us know if you’re facing any Wi-Fi connectivity issue after upgrading to iOS 5 or iOS 5.0.1 and if any of the tips mentioned above helped in resolving the issue.