There are a few common carpet problems that go hand in hand with cooler and wet weather. Quite often when the weather is less than stellar pets are reluctant to go outside to do their business. They often go near the doors they usually use to exit the house or hide behind furniture so you find a little present later. The odor will frequently not be noticeable until the weather heats back up.
Also moisture can get into the corners especially near thresholds to outside and at windows. Be aware of any building condensation in those areas when it comes to carpet. Moisture build up can cause mold and mildew issues which can usually be resolved with antimicrobial and fresh air. If the problem persists give us a call. After all..." If you want it clean, give it Extreme Steam!"