As we all know, night time is when you listen to faraway stations on the Medium Wave.

However, I've noticed now and then where more stations than usual are received during the day.

For example, yesterday, 2TM Tamworth was clearly audible all day, while Gunnedah, Moree, Muswellbrook, Dubbo and Cooma could be heard as well, although there was a bit of fading now and then. This is in addition to the usual Nowra, Orange, Lithgow, Wollongong, Newcastle and Canberra that a Sydney listener would expect to hear any day.

Has anyone else noticed improved conditions recently?

Apparently a lot of continuous wet weather affects ground waves.
JJ

In the USA we have daytime only AM stations. These would mask receivable DX we otherwise might hear. Does Australia have daytime only AM stations? Maybe a few around the very big cities?
Back in 1986 I was on holiday at Ayers Rock, and I had with me an AM/FM cassette recorder radio. During the day I could not find a single station on either band... Which would suggest that there's no shortage of full time radio frequencies available for radio station, though there's probably not enough listeners in many areas to economically support a station.

Back in the 70s the ABC stations, and the country commercial stations, would all shut down at around midnight. This cleared most of the band opening the way to receiving WA and overseas stations.

That is not the case today, almost all stations are owned by a few operators, and the content is networked, and they are all transmitting all the time.

I've never been to Ayer's Rock, but by now they might have a low-power community FM station to serve the tourists.

Does Australia have daytime only AM stations?

As far as I am aware all radio stations in Australia broadcast 24hrs, aside from perhaps some community and experimental stations.

2UW in Sydney was the first to go around the clock back in the late 1930s and there is a yarn that they have broadcast continually since then. 2UW shifted to the FM band before the Sydney Olympics and operates under the Ident "KIIS", pronounced kiss - yes, it is daft, isn't it - and transmits with the callsign 2WFM.

About 10 years ago on a camping trip on the Edward River near Moulamein, NSW, I was listening to 2YA (National Radio) Wellington, NZ, at night on a car radio. 2YA shares the same frequency as 2BH, Broken Hill on 567 kHz.

During the day I could receive 2BH though it was quite weak. As soon as it got dark 2BH would disappear & 2YA would romp in and only faded a few times during the night.. I believe 2YA once had the most powerful transmitter in the Southern Hemisphere, though I'm not sure if this is still the case.

In the very early days of broadcasting in Australasia daylight reception of Sydney stations was possible in Auckland & even included advertisements for the benefit of New Zealand listeners. Later on when the broadcast band started getting crowded Sydney listeners could receive the Auckland breakfast sessions before the local transmissions would fire up.

On the subject of 2UW, they went 24 hours in February 1935:

http://trove.nla.gov.au/newspaper/article/17156022/1119992