In the south east corner of the UK, my air plants seem to flower either in the late summer or in the late winter (very roughly).
It takes a long time for them to build up to it, rather like giving out ‘save the day’ cards to all their friends, and then faffing around for months about what to wear.
The main signs are flushing of leaves – green leaves getting a pinkish or reddish tinge to them. I have my suspicions about this Tillandsia ionantha:
The second is a change in the balance of growth or shape of the plant.
Above is a Tillandsia brachycaulos that I actually thought was protesting about poor light levels. It produced the stretched section of stem that you can see in the centre of the photo. I brought it home from the office and stuck it somewhere more conducive and within a couple of days I noticed that the leaves were flushing. Ah.
Tillandsia tectorum above, has recently started growing taller in the middle, which may be an indication that it is initiating flowering or it may not. If it is I will post more pictures.
Tillandsia seleriana above, shows no flushing, but a definite change in growth habit, with a paler section growing in a slightly different direction to the main plant. It took another month before the bud was visible.
Some plants, like Tillandsia fuchsii var. gracilis above just stick out a flower without warning. This was the first I noticed of this one. It may be that the slight bunching of the leaves in the centre was a clue.