I think maybe different regions should maybe come up with different names for their sabbats because though their practices can be similar, it will not be exactly the same. It's like how Beltane also has May Day, Walpurgisnacht and Samhain there is La Dias de los Muertos but they are not all the same thing and all come from different cultures.. Just saying how there are different seasons in different places, the wheel of the year can be reconstructed and celebrated in many ways and in place of traditional celebrations hailing from western Europe there should be celebrations that mirror that to fit other places on the same solstice/equinox/crossquarter but maybe under a different name since even the etymology of the sabbats have something to do with their practices. (Just a suggestion). Anyway I did refer to all of these by their seasonal equinox, solstices and crossquarters to make it more applicable.
Also I realized the wheel here in the Sonoran Desert feels reversed seasonally as opposed to the northern temperate coastal weather. Summer is incredibly hot and so unbearable the land feels unable to bear life, much like midwinter in a temperate zone is unable to bear life, though the reason for our winter is that it's too unbearably cold. Also where as the Sonoran Desert autumn begins to grow life, the temperate zone’s autumn begins to die, and the Desert’s spring is a great time for harvesting where the Temperate spring is a great time to sow seeds. And winter is still cold there but it's chilly and allows for life to grow a little and be nurtured in the cool dark resting phase before returning to the hotter weather. It doesn't mean practicing pagans in the desert should flip their sabbats like the southern hemisphere does, especially because their sunlight patterns are that of the northern hemisphere, but take into account what happens locally and how they should apply it to their celebrations. Some sabbat practices I noticed when I was first suggesting them were completely flipped such as Imbolc and Lammas, where as Imbolc is a time of cleansing and preparing for spring, and Lammas is a time to reap what you sow, in the Sonoran desert, Feb 1st is a time for reaping what was sown in autumn and August 1st is around the time the summer thunderstorms come to cleanse in preparation for the sowing season. I do think however the rest of the sabbats could be celebrated similarly to how it's celebrated in a temperate four seasonal climate but the 'reverseness' of the seasons to the temperate seasons should be acknowledged as well.
However some practices I want to add to my original suggestions are:
As the rains return to nurture the earth, celebrate this sabbat by nurturing yourself. Take a cooling shower, collect rain water for spells, honor this day as a point of rebirth for the showers bring on enough sustenance after the overbearing dry heat to allow life to grow again. (I'm unsure if rainsticks is exclusive to one culture, but if not) celebrate musically with rainsticks and drums for thunder. Clean the house, wash the floors, make some floating storm clouds for decoration if you are feeling crafty. Enchant a bowl of water with wishes and good intentions for how you would like yourself to grow and progress and cast the spell by drinking it and feeling it fill and cool your body.
Like how the author in the witchvox article that I have linked has said:
'One day I was planning my Samhain ritual and was thinking deeply about harvest. I was clearing out the straggling weeds from my garden getting ready to plant my Winter crops. Although I was getting ready to plant, I was still trying to ‘make it fit’ the classic harvest-festival mold by trying to generate some pseudo-harvest activity in my life to celebrate according to the Eurocentric calendar.'
I realized how another holiday local to the desert area though further south, in Mexico, La Dias de los Muertos is also about honoring the dead and ancestors but plants such as freshly grown flowers are used as decoration in this holiday. From what I've researched in this area of the desert, things begin to grow so their Autumn cross quarter is a lot like our Spring cross quarter. When celebrating Samhain in the sonoran desert one could honor their dead by planting new seeds and decorating their altar, home, and shrines dedicated to their past loved ones with seasonal blooms and flowers to represent life after death and also how the decay of the physical form returns to the earth and becomes flowers/ takes on new life. Also you could decorate with butterflies such as The Painted Lady which could be seen in this time of year. I noticed with images from La Dias de los Muertos they decorate with seasonal flowers that are in season during my local (temperate northeast) mid spring (Beltane) celebration such as Roses and Peonies (which just goes back to my theory/feeling that seasonally everything in this area of the desert feels reversed from my local temperate area). Also it is custom in many cultures with holidays that honor their dead loved ones to visit the cemetery and leave offerings so it would be a nice practice to leave seasonal blooms on your loved ones graves.
Just adding to the growth and growing crystals part. I originally said how growing crystals for this day could be super festive. Crystals are formed when minerals in a solution in high heat begin to cool slowly. One thing I noticed about this desert area is that a lot of things are able to grow in the winter since the earth has cooled down from the unbearable heat. Growing crystals can represent the growth of nature and of course food that happens in winter. It can even represent the growth of the self much like in a way if we have a lot going on and overwork (overheat) ourselves and the moment we get to cool down and take a break we can self reflect and understand how to grow and progress from there. Also crystals sometimes can look cool and icy and I know it does not snow so much over there but it can give a christmas-like feel without representing iciness/frost that might not always be native to this area, but instead something that can apply more to the local nature in a metaphorical way.
Just adding that desert mistletoe is blooming and it smells sweet and is the welcomer of spring in the desert. It would be great to decorate the altar and home with. It also attracts bees and when the berries form, it brings the birds. Imbolc is a sabbat that honors the budding of the earth so this can apply here where the budding of mistletoe attracts spring-like creatures.
Spring CrossQuarter/Beltane:
This sabbat marks the end of Spring and looks towards the midsummer drought. It's much like how samhain in a temperate climate is a season where plants begin to change color and die and everything is dying and becoming colder yet here everything is getting hotter and dryer. Beltane is also a fire festival so here fire can be applied that the sun is heating up the earth. Light a bonfire, if you like flamethrowing or know people who can do it, fire dancing is cool. Decorate or wear faded colors. This can represent the ghostly spirits that will be closer to our world now the veil is thin or the intensity of the sun due to the foresummer drought bleaching and drying the earth.
I found this Almanac that’s organized by the seasonal moons of the Tohono O’odham months, it's old but informational.