Our weekly roundup of what we're seeing sizzle (and fizzle) on the red carpet.

Splash News Online; Startraks; Getty

In our weekly round-up of what we’re seeing sizzle (and fizzle) on the red carpet, we noticed some eye-catching, gem-encrusted ensembles, stars stepping out in dresses with out-of-the-box necklines — and one celeb in a sweatshirt despite the 90° weather. Consider this your fashion forecast.

Up: Bejeweled ensembles. Two of the most talked about (and most loved) looks this week shared a common thread: gem embellishments! We’re still gushing over how flawless Blake Lively looked in her Burberry separates (89 percent of you agree!), and Kate Hudson also shined in her high-low Elie Saab gown. Also bringing it in the high-shine, sparkle-factor department: Emma Roberts in her white Edition by Georges Chakra romper and Mary-Louise Parker’s sequin Memeka by Gustavo Cadile dress.

Up: Unusual necklines. Stars stepped out in a array of dresses with interesting necklines (some good, some less so). Salma Hayek led he pack with the beaded silver neckline on her sexy Saint Laurent mini. Olivia Munn commanded attention in a black, double-slit Thakoon dress with a decorative strip of fabric across her collar bone. Looking similarly fashion-foward, Octavia Spencer’s Tadashi Shoji dress had a scrollwork-esque boatneck and Maria Sharapova’s Valentino frock combined sheer panels with a prim collar.

Down: Sweatshirts in summer. While most of Hollywood went simple and sleeveless this week (hey, Diane Kruger!), one celeb braved the heat in a long-sleeved topper, leather pants and a skirt. Yes, we’re talking about Ciara, who despite the high temps in N.Y.C., was completely covered up head-to-toe. Maybe the singer was trying to show less skin after going super-bare last week, but we don’t think this particular look will be catching on until September for most stars.

For more on which trends to follow, check out our thoughts on hot-weather leather and super-straight strands.

–Brittany Talarico