Hey, stevegoldsmith!
Welcome to the AGL Community!
Seasonal variances do definitely impact all solar systems, simply due to to the fact that the sun is out more in summer than it is winter! However, it may be worth double checking a few things here given your system exported more power in June/July (387 kWh) than it did in January/February (194 kWh). The best place to start is by checking your inverter for any warning lights/messages.
In the case that you have a Net metering configuration at your property, it's also important to keep in mind that any additional consumption within your property (e.g. using the air conditioner heavily throughout summer) will have an impact on power that you export, as this will diminish the amount of surplus power that you're left with.
If there is anything else that we can help with or clarify, please get back in touch!
Cheers,
Jayden