If you are in auto exposure mode this won't happen. In the shutter priority mode the ISO will be locked at ISO 100. Allowing the ISO to bump up the gain on the sensor is really just adding noise to the images which makes them harder to process.
If it really was bright and sunny outside the camera would likely have selected a much higher exposure time in Auto mode.
If you don't like that automatic speed limitation you can turn it off in the Settings menu.